The Doctor leaned against the wall in one of The TARDIS corridors, one foot against the wall, frowning at the psychic paper in his hand. The door next to him opened and Zara stepped out, soaking wet and a white towel wrapped around her, letting out a small yelp.

"Ever heard of it?" The Doctor muttered.

Zara let out a breath, peering over at the psychic paper, written with the message "The Library. Come as soon as you can. X" on it.

"The Library." Zara nodded. "The whole planet is a library. Boe had a book on it. Ironic really."

"Hm." The Doctor looked up, finally looking at her, his jaw dropping slightly at the sight of her.

Zara frowned, "What?"

"Um." He gulped, looking her up and down. Why was she so distracting?! "Nothing."

"Think we should check it out?"

"What?"

She laughed, snatching the psychic paper from him, "This. The Library." She smiled at him, walking off down the hallway, The Doctor watching her as she went.

"Uh." He stammered before following after her.

...

"Books!" The Doctor cheered. "People never really stop loving books." He grabbed his coat and headed towards the door, Donna and Zara following.

...

The three of them stepped out into a large but empty reception, light streaming in from the windows above.

"51st century." The Doctor said, striding across the room.

Zara laughed, skipping after him, "By now you've got holovids, direct-to-brain downloads, fiction mist." She explained to Donna. "But you need the smell. The smell of books, Donna. Deep breath." The Doctor opened a door, moving out of the way to let Zara through with a smile.

...

They made their way into a large, columned area and down some steps to a balcony, overlooking the rest of the library.

"The Library." The Doctor smiled, taking Zara's hand. "So big, it doesn't need a name-just a great big the."

"It's like a city!" Donna gasped.

"It's a world-literally a world. The whole core of the planet is the index computer-the biggest hard drive ever. And up here, every book ever written. Jeffrey Archer, Bridget Jones, Monty Python's Big Red Book. Brand new editions specially printed. We're near the equator, so..." He licked his finger, holding it up in the air. "This must be biographies! I love biographies."

"Yeah, very "you". Always a death at the end."

"You need a good death. Without death there'd only be comedies. Dying gives us size." He smiled, putting his arm around Zara's shoulder, placing a kiss on her head. "Especially if there's someone worth dying for."

Donna picked up a book, Zara snatching it from her grasp, "Oi! Spoilers!" She laughed.

"What?" Donna asked.

"These books are from your future." Zara smiled, throwing the book aside. "You don't want to read ahead and spoil the surprises. Like peeking at the end."

"Isn't travelling with you two one big spoiler?"

The Doctor frowned, "We try to keep you away from major plot developments...which, to be honest, I seem very bad at, cause you know what? This is the biggest library in the universe...so where is everyone. It's silent." He took out the sonic, moving over to the information kiosk.

"The Library?"

"The planet. The whole planet."

"Well...maybe it's a Sunday."

"No." Zara shook her head. "We never land on Sundays. He says Sundays are boring."

"They are!" The Doctor argued.

"Well, maybe everyone's really, really quiet." Donna suggested.

"Yeah, maybe. But they'd still show up on the system."

"Doctor, Zara, why are we here? Really why?"

"Oh, you know, just...passing."

"No. Seriously, it was, "Oh, let's hit the beach" then suddenly we're in a library. Why?"

Zara peered in closer at the screen, "Now that's interesting." She muttered.

"What?"

"Scanning for lifeforms. If I do a scan for your basic humanoids-you know, your book readers, few limbs and a face-apart from us, I get nothing. Zippo. Nada. See? Nobody home. But if I widen the parameters to any kind of life..." She tapped on the keyboard with a frown, the count increasing until it read 'Error'. "A million million. It gives up after that. A million million."

"But there's nothing here."

"And not a sound." The Doctor muttered. "A million million lifeforms...and silence in The Library."

"But there's no one here. There's just books. I mean, it's not the books, is it? I mean, it can't be the books, can it? I mean, books can't be alive."

Zara watched, amused, as The Doctor and Donna carefully reached out to a book on the balcony.

"Welcome!" A voice called from reception, startling the three of them.

Donna pointed behind them, "That came from in there." She gulped.

"Yeah." The Doctor nodded, the three of them turning and heading back the way they came.

...

The three of them walked back in, a clicking and whirring sound filling the air as a white statue by the information booth slowly turned to face them, bearing a female human face.

"I am Courtesy Node 710/Aqua." The Node said. "Please enjoy The Library and respect the personal access codes of all you fellow readers regardless of species or hygiene taboo."

Donna frowed, "That face, it looks real."

"Yeah." The Doctor muttered. "Don't worry about it."

"A statue with a real face, though? It's a hologram or something, isn't it?"

"No, but really, it's...fine."

"Additional." The Node continued. "There follows a brief message from the Head Librarian for urgent attention. It has been edited for tone and content by the Felman Lux Automated Decency Filter. Message follows. 'Run. For God's sake, run. Nowhere is safe. The Library has sealed itself. We can't-Oh, they're here. Argh, slarg, snick.' Message ends. Please switch off your mobile comm. units for the comfort of other readers."

"So that's why we're here?" Zara remarked calmly. "Any other messages, same date stamp?"

"One additional message. This message carries a Felman Lux Coherency Warning of 5-0-11-"

"Yeah, yeah." The Doctor interrupted, rolling his eyes. "Fine, fine, fine. Just play it."

"Message follows. "Count the shadows. For God's sake, remember-if you want to live, count the shadows." Message ends."

The Doctor frowned, looking around the empty room, "Zar, Donna..." He muttered.

"Yeah?" Donna asked nervously.

"Stay out of the shadows." He turned back round to see Zara already heading through another door. He rolled his eyes, still after all this time waiting for Martha to pull him after her, before following after her.

"Why?" Donna asked, following after him. "What's in the shadows?"

...

The three of them walked down a aisle lined high by bookshelves.

"So...we weren't just in the neighbourhood. " Donna muttered.

"Yeah, we kind of sort of lied a bit." The Doctor nodded. "We got a message on the psychic paper." He held up the psychic paper to Donna, showing her the message. "What do you think? Cry for help?"

Donna took it from him, "Cry for help...with a kiss."

"Oh, we've done all that." He shrugged, taking it back.

"Who's it from?"

"No idea."

"So why did we come here? Why did you..."

Zara looked round with a frown as the lights behind them began to switch off one by one heading towards them, "Doctor, Donna." She mumbled.

"What's happening?" Donna asked as she and The Doctor looked back.

The Doctor grabbed Zara's hand, "Run!" He shouted.

The three of them bolted down the corridor away from the darkness and stopped at a door, pulling at it only for it to stay shut.

"What, is it locked?" Donna asked.

"Jammed!" The Doctor snapped through gritted teeth. "The wood's warped!"

"Well, sonic it! Use the thingy!"

"We can't!" Zara gulped. "It's wood!"

"What, and it doesn't do wood?"

"Hang on, hang on, hang on." The Doctor said, taking out the sonic, trying to use it on the door. "If I can vibrate the molecules, fry the bindings, I can shatterline the interface..."

"Oh, get out of the way!" Donna snapped, pushing the two of them out of the way before kicking the door open.

The three of them ran in and The Doctor grabbed a book, pushing it through the door handles. With a breath of relief the three of them turned to be met face to face with a floating gold sphere, a security camera.

"Oh, hello." The Doctor smiled. "Sorry to burst in on you like this. Okay if we stop here for a bit?"

The sphere suddenly dropped to the floor.

"What is it?" Donna asked as they approached it.

"Security camera." The Doctor said, kicking it gently.

Zara frowned at his action, "Switched itself off." She said, picking it up.

The Doctor took out the sonic and started using it on the camera, "Nice door skills, Donna."

"Well, you know, boyfriends." Donna shrugged. "Sometimes you need the element of surprise. What was that? What was after us? I mean, did we just run away from a power cut?"

"Possibly."

She glanced up at a skylight, "Are we safe here?"

Zara smiled at her, "Of course we're safe."

The Doctor nodded, "There's a little shop." A flap opened on the camera. "Gotcha!"

No, stop it. A message scrolled across the screen on the camera.

"Oh, I'm sorry." The Doctor apologised quickly. "I really am." He set it down on the floor. "I'm sorry. I'm so sorry."

"It's alive." Zara mumbled.

Donna frowned, "You said it was a security camera."

The Doctor stood back up, "It is. It's an alive one." He looked back at Zara guiltily, putting away the sonic.

Others are coming. Another message read.

"What does it mean, "others"?" Donna asked before noticing another Node and walking over. "Excuse me, what does it mean, "others"?"

The Doctor shook his head, "That's barely more than a Speak-Your-Weight machine. It can't help you."

"So why's it got a face?"

"This flesh aspect was donated by Mark Chambers on the occasion of his death." The Node, bearing a male face, said.

Donna turned back to The Doctor and Zara, stunned, "It's a real face!"

"It has been actualised individually for you from the many facial aspects saved to our extensive flesh banks. Please enjoy."

"It chose me a dead face it thought I'd like? That statue's got a dead person's face on it!"

"It's the 51st century." Zara shrugged. "That's basically like donating a park bench."

"It's donating a face!" She began to back away.

"Oh, wait!" The Doctor yelped. "No!" He grabbed her around the waist, pulling her out of a shadow.

"Hands!" She snapped, slapping his arms away.

"The shadow. Look." Zara said, the three of them looking down at it.

"What about it?"

"Count the shadows."

"One. There, I counted it. One shadow."

"Yeah, but what's casting it?" The Doctor muttered, looking around to find nothing to cast the shadow. "Oh! I'm thick! Look at me; I'm old and thick! Head's too full of stuff, I need a bigger head!" He smacked his head, Zara watching him in amusement.

The light in the corridor began to buzz and dim, the light starting to go.

"The power must be going." Donna remarked.

"This place runs on fission cells." Zara muttered. "They'll outburn the sun."

"Then why is it dark?"

"It's not dark."

Donna turned her head and nervously reached out for The Doctor and Zara's arms.

"That shadow-it's gone."

"We need to get back to the TARDIS." The Doctor breathed, putting his arm around Zara's waist. The two of them shared a look. If this was what they both thought it was, they had to get Donna out, quick.

"Why?"

"Because that shadow hasn't gone, it's moved."

"Reminder: The Library has been breached." The Node announced. "Others are coming." It kept repeating itself as Zara wriggled out of The Doctor's grasp, walking forward and looking at a door in front of them before The Doctor could pull her back.

Suddenly there was a loud blast and a bright light, making The Doctor and Donna wince as Zara stood with no reaction, watching as six figures spacesuits entered through the breached door. The leader of the group stepped forward, stopping in front of Zara before pressing a switch on the helmet. The visor cleared to reveal a blonde, curly haired, smiling woman.

"Hello, sweeties." The woman smiled at Zara before looking back at The Doctor.

The Doctor instinctively stepped forward, putting an arm in front of Zara, "Get out." He said sharply.

"Doctor, Zara." Donna called over warningly.

"All of you, turn around, get back in your rocket and fly away! Tell your grandchildren you came to The Library and lived. They won't believe you."

"Pop your helmets, everyone." The woman called back to her team. "We got breathers." She took off her helmet, shaking her hair that was pulled into a ponytail and everyone followed except for a woman, Anita.

"How do you know they're not androids?" Anita called.

"'Cause I've dated androids. They're rubbish."

Anita nodded, taking off her helmet revealing a black woman with short black hair.

"Who is this?" A stout, bald man, Lux, snapped. "You said we were the only expedition. I paid for exclusives."

"I lied. I'm always lying. Bound to be others."

Lux turned to a young brunette woman, "Miss Evangelista, I want to see the contracts." Miss Evangelista nodded at him.

The woman turned back to The Doctor and Zara, "You came through the north door, yeah?" She asked. "How was that, much damage?"

"Please, just leave." The Doctor begged, squeezing Zara's arm. "I'm asking you seriously and properly, just leave-"

"Hang on, did you say, "expedition"?" Zara interrupted.

"My expedition." Lux called over. "I funded it."

"Oh, you're not, are you?" The Doctor groaned. "Tell me you're not archaeologists."

The woman raised an eyebrow at him, "Got a problem with archaeologists?"

The Doctor gestured between him and Zara, "We're time travellers-" Zara gave him a look and he stammered slightly. "I point and laugh at archaeologists." He gave an awkward cough as the woman laughed.

"Ah." The woman nodded, holding out her hand to The Doctor. "Professor River Song, archaeologist."

The Doctor shook her hand, "River Song, lovely name. As you're leaving-and you're leaving now-you need to send up a quarantine beacon. Code-wall the planet, the whole planet. Nobody comes here, not ever again. Not one living thing, not here, not ever!"

Zara glanced over as Anita began to wander out of the light, "Um, excuse me!" She shouted.

The Doctor followed her gaze and ran over to Anita, "What's your name?"

"Anita." Anita stammered.

"Anita, stay out of the shadows." He pulled her back. "Not a foot, not a finger in the shadows till you're safely back in your ship. Goes for all of you. Stay in the light! Find a nice bright spot and just stand. If you understand me, look very scared." They all looked at him, bemused as River and Zara shared a look. "No...a bit more scared than that." Miss Evangelista gulped. "Okay, do for now." He turned and walked over to a black man with curly hair. "Who are you?"

"Uh, Dave." He replied.

"Okay, Dave..."

"Well, Other Dave, because, uh...that's Proper Dave, the pilot." He nodded over at a white man with black hair. "He was the first Dave so when we-"

"Well, Other Dave, the way you came, does it look the same as before?"

"Yeah." Other Dave nodded, glancing down the hallway they all appeared down to find that the lights had dimmed. "Oh, it's a bit darker."

"How much darker?" Zara called over.

"Well, like I could see where we came through just a moment ago. I can't now."

"Seal up this door." The Doctor ordered. "We'll find another way out." He headed back to the centre of the room, taking Zara's hand.

"We're not looking for a way out." Lux snapped. "Miss Evangelista?"

Miss Evangelista scurried up to The Doctor, Donna and Zara, "I'm Mr Lux's personal...everything." She stammered, holding out a contract to them. "You need to sign these contracts agreeing that your individual experiences inside The Library are the intellectual property of the Felman Lux Corporation."

"Right." The Doctor nodded. "Give it here." He took a contract, handing one to Zara.

"Yeah." Donna agreed, taking one.

Without sharing a look, the three of them ripped the contracts in half, throwing them to the floor.

"My family built this library, I have rights." Lux snapped.

River rolled her eyes, "You have a mouth that won't stop." She turned to Zara and The Doctor. "You think there's danger here?"

"Something came to this library and killed everything in it." The Doctor said sarcastically. "Killed a whole world. Danger? Could be."

"That was 100 years ago. The Library's been silent for 100 years. Whatever came here is long dead."

"Bet your life?"

She smirked at him, "Always."

They all looked round at the sound of whirring to find Other Dave sealing the door.

"What are you doing?" Lux asked.

"He said seal the door." Other Dave shrugged.

"Torch!" The Doctor called, snatching the torch from Lux.

"You're taking orders from him?" Lux gaped.

"Spooky, isn't it?" Zara laughed sarcastically, moving over next to The Doctor with Donna as he shone the torch into the shadows. "Almost every species in the universe has an irrational fear of the dark. But they're wrong-'cause it's not irrational. It's Vashta Nerada."

"What's Vashta Nerada?" Donna asked.

"It's what's in the dark. It's what's always in the dark."

"Lights!" The Doctor called. "That's what we need-lights!" He turned and tossed the torch to Lux. "Ya got lights? Form a circle, safe area, big as you can, lights pointing out."

River turned to Anita, "Oi, do as he says."

The Doctor took off his coat, throwing it onto a desk and placing a kiss to Zara's cheek as he went, making River smile lovingly at the two of them as Zara rolled her eyes at him.

"You're not listening to this man?" Lux asked.

"Apparently, I am." River nodded. "Anita, unpack the lights. Other Dave, make sure the door is secure then help Anita. Mr Lux, put your helmet back on, block the visor. Proper Dave, find an archive terminal. I want you to access The Library database, see what you can find about what happened 100 years ago. Pretty Boy, Psycho Girl, you're with me. Step into my office." She turned and walked over to a desk with a terminal as Zara watched The Doctor kneel, head sideways on the floor, watching the shadows and the team did as they were told.

"Professor Song, why am I the only one wearing my helmet?"

River smirked, "I don't fancy you."

The Doctor got up and moved over to help Proper Dave as Zara watched River carefully, heading over to her.

"Probably I can help you." The Doctor muttered.

River rolled her eyes, "Pretty Boy, with me I said!" She called over to The Doctor.

The Doctor looked at Zara, pointing at himself, "Oh, I'm Pretty Boy?"

"Yes." Zara nodded.

Donna smirked, "Oh, that came out a bit quick." She remarked.

The Doctor mocked glared at her, "Shutup Donna." He muttered, looking back to Zara as River laughed. "Pretty?"

"Meh." She shrugged, smiling and holding out her hand to him.

The Doctor rolled his eyes, making his way over to River, "Don't let your shadows cross!" He called, taking Zara's hand. "Seriously, don't even let them touch! Any of them could be infected."

"How could a shadow be infected?" Other Dave asked.

The Doctor shook his head, ignoring the man, and put his arm around Zara's waist, placing a kiss to her head, watching as River unpacked her bag. The Doctor and Zara shared a look before The Doctor cleared his throat.

"Thanks." River remarked.

"For what?" The Doctor frowned.

"The usual. For coming when I call."

"That was you?" Zara asked.

"You're doing a very good job, acting like you don't know me. I'm assuming there's a reason." She took out a small blue diary, designed to look like The TARDIS, thumbing through it.

"A fairly good one, actually." The Doctor muttered.

"Okay, shall we do diaries, then? Where are we this time?" She looked up at them and stared carefully. "Going by your face, I'd say it's early days for you, yeah? So, um... "Crash of the Byzantium", have we done that yet?" The Doctor stared at her, tightening his grip on Zara nervously. "Obviously ringing no bells." She flipped through the diary as Zara frowned, noticing the cover resembled the front of The TARDIS. "All right, um...oh..."picnic at Asgard". Have we done Asgard yet?" The two of them stared back with no response, making River raise an eyebrow at them. "Obviously not." She looked between them. "Blimey, very early days, then. Huh, life with time travellers-never knew it could be such hard work. Um..." She looked back up from the book at them. "Look at you two." She breathed. "You're young."

"I'm really not, you know." The Doctor replied.

"No, but you are." She put a hand each on one of their cheeks. "Your eyes... You're younger than I've ever seen either of you."

"You've seen us before, then?"

"Doctor, Zara..." She breathed heartbrokenly. "Please tell me you know who I am."

"Who are you?" Zara asked sadly.

River pulled away, staring at Zara in horror as a ringing round filled the air and The Doctor looked around.

"Sorry, that was me." Proper Dave called over from a terminal. "Trying to get through into the security protocols. I seem to have set something off. What is that? Is that an alarm?"

"Doctor, that sounds like-" Donna began.

"It is." The Doctor nodded. "It's a phone."

Proper Dave shook his head, "I'm trying to call up the data core but it's not responding, just that noise."

The Doctor took Zara's hand and made his way across the room. Zara glanced back at River over her shoulder before looking back round, heading to the terminal followed by Donna, River and the others.

Donna frowned, "But it's a phone."

The Doctor scratched his head, "Um-"

Zara rolled her eyes, "Let me try." She took over from Proper Dave, typing on the terminal as River let out a small laugh. Zara glanced at her in the reflection before continuing to type, The Doctor putting his arm round her waist, squeezing her hip when "Access Denied" flashed across the screen. "Okay, doesn't like that." She sighed. "Let's try something else." She pressed another button and the screen began to show an image. "Okay, here it comes." Static flashed before it showed the image of a young girl in a living room.

"Hello?" The Doctor called.

"Hello." The girl blinked. "Are you in my television?"

"Well...no, We're-we're sort of in space. Um, I was, well Zara here," He winked at Zara. "Genius here, she was trying to call up the data core triple-grid security processor."

The girl frowned, "Would you like to speak to my dad?"

"Dad or your mum. That'd be lovely."

"I know you. You were in my library."

"Your library?"

"The Library's never been on television before. What have you done?"

"Um," Zara stammered. "Well, um...I just...rerouted the interface-" The screen suddenly cut off, making The Doctor and Zara jerk back.

"What happened?" River asked. "Who was that?"

"Bloody..." Zara muttered, pressing buttons, only for the screen to read "Access Denied". "Keep working on those lights! We need lights!" She turned and ran over to a monitor at the desk, The Doctor following after her.

"You heard her, people." River called. "Let there be light."

Zara typed on the monitor furiously as The Doctor's eye wandered towards River's diary sitting beside it. He shared a look with Zara before he reached out and picked it up, only for River to come up behind him.

"Sorry." She said, snatching the diary away. "You're not allowed to see inside the book. It's against the rules."

"What rules?" Zara asked, returning to the monitor.

"Your rules." She turned and walked away.

Zara let out a sigh, "Know her?" She mumbled.

The Doctor shook his head, "No. You?"

"She..." She glanced back at River. "Dunno. Seems, not familiar, but..."

Suddenly, books starting flying off the shelves, Zara watching in amusement.

"What's that?" The Doctor frowned. "Zara didn't do that. Did you do that?!"

Proper Dave shook his head, "Not me."

"CAL-Access Denied" flashed across the screen, making Zara bite her lip.

"What's "CAL"?" She asked aloud.

Miss Evangelista whimpered as everyone watched in amazement before the books eventually stopped.

Zara looked over at Donna as she walked over to Miss Evangelista and talk to the woman when The Doctor squeezed her hip again, shaking her from her thoughts.

"Hm?" She mumbled, making her look up at The Doctor.

"You ok?" The Doctor asked quietly.

"Mhmm."

"What's causing that?" River asked, glancing round at the clattering books. "Is it the little girl?"

"Well, who is the little girl?" The Doctor asked, sitting on the desk, wrapping his arms round Zara's waist. "What's she got to do with this place?"

"Wonder what her name is." Zara shrugged, making everyone look at her, confused. The Doctor shook his head, squeezing her tightly. "Anyway, back on subject. How does the data core work? What's the principle? What's CAL?" She hesitated for a second. "Hm, what about Charlotte? Pretty name, Charlotte. So's Melody." River gave her a small smile as The Doctor frowned at her in amusement.

River shook her head, "Ask Mr Lux."

"CAL." The Doctor said, looking to Lux. "What is it?"

"I'm sorry." Lux replied. "You didn't sign your personal experience contracts."

The Doctor jumped down from the desk, advancing towards Lux, "Mr Lux, right now, you're in more danger than you've ever been in your whole life and I am not letting you drag her," He violently pointed behind him at Zara. "Into that danger either. You're protecting a patent?"

"I'm protecting my family's pride."

"Funny thing, Mr Lux, I don't wanna see everyone in this room dead because some idiot thinks his pride is more important."

"Then why didn't you sign his contract?" River asked, making Zara and The Doctor stare at her. "I didn't either. I'm getting worse than you two."

"Okay, okay, okay." Zara sighed in frustration. "Let's start it again. What happened here? On the actual day 100 years ago, what physically happened?"

Suddenly, a panel in the wall slid up, revealing a passageway, only for it to be unnoticed by everyone.

"There was a message from The Library." River replied. "Just one. "The lights are going out." Then the computer sealed the planet, and there was nothing for 100 years."

Miss Evangelista looked over and noticed the passageway.

"It's taken three generations of my family just to decode the seals and get back here." Lux sighed.

"Um, excuse me." Miss Evangelista called.

"Not just now." Lux snapped.

"There was one other thing in the last message." River began cautiously.

Lux glared at her, "That's confidential."

River glared back at him, "I trust this man and woman with my life...with everything."

"You've only just met them."

"Nope. They've only just met me."

The Doctor and Zara looked over at Donna before moving over to River as Miss Evangelista stood by the open panel.

"Um, this might be important actually." She called nervously.

"In a moment." Lux snapped sternly.

River showed The Doctor and Zara a data file, "This is a data extract that came with the message."

"4022 saved. No survivors." Zara read.

"4022-that's the exact number of people who were in the library when the planet was sealed."

"But how can 4022 people be saved if there were no survivors?" Donna frowned.

"That's what we're here to find out."

"So far what we haven't found are any bodies." Lux sighed.

River looked over at Zara and the two of them shared a look, River staring at her sadly.

"Hello Zaranthea." River mouthed to Zara, making her stare in confusion, horrified.

Suddenly a scream filled the air, shaking everyone from their thoughts. The Doctor looked over at the passageway and took Zara's hand, running through the passage, others following.

...

The group made their way into a small seated area filled with shelves of books to find a skeleton sitting on a chair, stripped of it's flesh.

"Everybody careful." The Doctor warned. "Stay in the light."

"You keep saying that." Proper Dave said. "I don't see the point."

"Who screamed?"

"Miss Evangelista."

"Where is she?"

River pressed her comm, "Miss Evangelista, please state your current-" She stopped suddenly as they all heard the echo and The Doctor pointed his torch over at the suit on the skeleton. "Please state your current..." She walked over and knelt down. "Position." She pulled at the broken collar to reveal the the green lights of the comm. "It's her, It's Miss Evangelista."

"We heard her scream a few seconds ago." Anita frowned. "What could do that to a person in a few seconds?"

"It took less than a few seconds." Zara breathed.

"What did?"

"Hello?" Miss Evangelista's voice called over the comm.

"I'm sorry, everyone." River gulped. "This isn't going to be pleasant. She's ghosting."

"She's what?" Donna frowned.

"Hello?" Miss Evangelista called. "Excuse me. I-I'm sorry, hello? Excuse me."

"That's-that's her. That's Miss Evangelista."

"I don't wanna sound horrible," Proper Dave mumbled. "But couldn't we just...you know-"

"This is her last moment...no we can't." River snapped. "A little respect, thank you."

"Sorry, where am I?" Miss Evangelista asked. "Excuse me."

"But that's Miss Evangelista." Donna breathed.

"It's a data ghost. She'll be gone in a moment." River sighed. "Miss Evangelista, you're fine." She said into the comm. "Just relax; we'll be with you presently."

Donna looked to The Doctor and Zara, "What's a data ghost?"

"There's a neural relay in the communicator, let's you send thought mail." Zara explained. "That's it there, those green lights. Sometimes it can hold an impression of a living consciousness for a short time after death. Like an after-image."

"My father lasted a day." Anita said. "Kept talking about his shoelaces."

"She's in there." Donna breathed.

"I can't see." Miss Evangelista gasped over the comm. "I can't...Where am I?"

"She's just brainwaves now." Proper Dave sighed. "Pattern won't hold for long."

"She's conscious." Donna gasped. "She's thinking."

"I can't see." Miss Evangelista sobbed. "I can't...I don't know what I'm thinking."

The Doctor wrapped an arm around Zara's waist, "She's a footprint on the beach and the tide's coming in." He said quietly.

"Where's that woman?" Miss Evangelista asked. "The nice woman...is she there?"

"What woman?" Lux frowned.

"She means..." Donna gulped. "I think, she means me."

"Is she there?" Miss Evangelista asked.

"Yes, she's here." River nodded. "Hang on." She pressed a button on the comm, putting it on speaker. "Go ahead. She can hear you."

"Hello, are you there?"

Donna gasped and shook her head.

"Help her." The Doctor whispered.

"She's dead." Donna gulped.

"Yeah, help her."

"Hello?" Miss Evangelista called. "Is that the nice woman?"

"Yeah." Donna gulped, stepping forward. "Hello. Yeah, I'm-I'm here. You okay?"

"What I said before, about being stupid, don't tell the others. They'll only laugh."

"'Course I won't. 'Course I won't tell them."

"Don't tell the others. They'll only laugh."

"I won't tell them. I said I won't."

"Don't tell the others. They'll only laugh."

"I'm not going to tell them."

The indicator lights of the neural relay began to flash, River looking at it sadly.

"Don't tell the others. They'll only laugh."

"She's looping now." River said quietly. "The pattern's degrading."

"I can't think." Miss Evangelista gasped. "I...don't know...I...I...I...Ice cream. Ice cream. Ice cream. Ice cream. Ice cream." She began to repeat herself.

"Does anybody mind if I..." River gently stepped forward and broke off the relay.

"That was...that was horrible." Donna gasped tearfully, The Doctor and Zara putting a hand on her shoulder. "That was the most horrible thing I've ever seen."

"No..." River said sadly, looking at the comm in her hand. "Just a freak of technology." She pocketed the comm, looking back at Zara and The Doctor. "But whatever did this to her, whatever killed her, I'd like a word with that."

"I'll introduce you." The Doctor sighed, Zara leaving the room, and followed after her.

...

The Doctor and Zara ran back into the previous room with the others following, The Doctor shining a torch about.

"I'm gonna need a packed lunch." The Doctor called over his shoulder.

"Hang on." River said, kneeling down to her bag.

Zara and The Doctor knelt down next to her, "What's in that book?" The Doctor asked.

"Spoilers."

"Who are you?" Zara asked.

"Professor River Song, University of-"

"To us. Who are you to me and The Doctor?"

"Again...spoilers." She held out a metal box with food inside to The Doctor. "Chicken and a bit of salad. Knock yourself out."

The Doctor took the box from her, "Right, you lot!" He called, standing up. "Let's all meet the Vashta Nerada."

...

The Doctor knelt on his knees, sonicing under the table at the shadows as Zara watched carefully, sitting next to him cross legged as River watched the two of them lovingly, Donna next to her.

"You travel with them, don't you?" River asked. "The Doctor and Zara-you travel with them."

Donna eyed her, "What of it?"

The Doctor glanced at Proper Dave next to him, "Proper Dave, can you move a bit?"

"Why?" Proper Dave asked.

"Over there by the water cooler."

Proper Dave reluctantly moved out of the way and The Doctor glanced back at Zara, giving her a small smile before continuing to sonic the shadows.

"You know them, don't you?" Donna asked.

River smiled, "Oh, God, do I know that man and woman. We go way back, those two and me...just not this far back."

"I'm sorry, what?"

"They haven't met me yet. I sent them a message but it went wrong. It arrived too early. This is the Doctor and Zara in the days before they knew me. And they look at me... they look right through me, and it shouldn't kill me, but it does."

"What are you talking about?" Donna snapped. "Are you talking rubbish? Do you know them or don't you?"

"Donna!" The Doctor and Zara called over their shoulders.

"Quiet," The Doctor said. "I'm working."

"Sorry." Donna muttered.

River looked at Donna, shocked, "Donna. You're Donna, Donna Noble."

"Yeah. Why?"

"I do know the Doctor and Zara, but in the future-their personal future."

The Doctor's ears perked up at that thought. The thought of him and Zara, their future, like the two of them as a whole. The Doctor and Zara in The TARDIS with their companion, not like it had been before when it had been The Doctor travelling in The TARDIS with Martha and Zara.

"So why don't you know me?" Donna asked. "Where am I in the future?"

"Doctor!" Zara gasped suddenly.

The Doctor shook out of his thoughts, "Okay, got a live one!" He called, getting up and pulling Zara with him and they turned to face the others. "That's not darkness down those corridors. This..." He pointed into the shadow. "Is not a shadow. It's a swarm..." He picked up the lunch box. "A man-eating swarm." He threw the chicken leg into the shadow and the flesh stipped into nothing before it hit the floor. "They're piranhas of they air. The Vashta Nerada-literally "the shadows that melt the flesh." Most planets will have them but usually in small clusters. I've never seen an infestation on this scale-or as aggressive."

"What do you mean, "most planets"?" Donna asked. "Not Earth."

"Mmm, Earth and a billion other worlds."

Zara whacked him in the chest, glaring at him, "Where there's meat, there's Vashta Nerada." She explained. "You can see them sometimes if you look. Dust in sunbeams."

Donna frowned, "If they were on Earth, we'd know."

"Nah." The Doctor shook his head. "Normally they live on road kill. But sometimes people go missing. Not everyone comes back out of the dark."

"Every shadow?" River asked.

"No, but any shadow."

"So what do we do?"

"The Face of Boe taught me a lot of things." Zara laughed dryly. "Daleks, aim for the eyestalk. Sontarans, back of the neck. Vashta Nerada...run. Just run."

"Run? Run where?"

"This is an index point." The Doctor said, looking around. "There must be an exit teleport somewhere." He looked over at Lux with a questioning look.

"Don't look at me." Lux shrugged. "I haven't memorized the schematics."

"Doctor, the little shop." Donna suddenly said. "They always make you go through the little shop on the way out so they can sell you stuff."

The Doctor ran to the shop doorway and peered inside.

"You're right." He nodded. "Brilliant! That's why I like the little shop.

Proper Dave nodded, "Okay, let's move it."

Zara looked over at the man and her face dropped, notcing one shadow behind him and one to his side.

"Actually, Proper Dave, can you stay where you are for a moment?" She asked softly as The Doctor followed her gaze.

"Why?"

"I'm sorry. I'm so, so sorry. But you've got two shadows."

Everyone followed Zara's gaze as she gulped.

"It's how they hunt." The Doctor called over, straightening with worry. Zara was in the room! Normally, he wouldn't fear as much for her because she was smart and looked after him more than he looked after her, but with River around... He had no idea who she was but she knew them. And right now it was setting off alarm bells in his head to get Zara out of there. "They latch onto a food source and keep it fresh."

"What do I do?" Proper Dave asked nervously.

"You stay absolutely still, like there's a wasp in the room. Like there's a million wasps."

"We're not leaving you, Dave." River called over reassuringly.

"'Course we're not leaving you. Where's your helmet? Don't point, just tell me."

Proper Dave gulped, "On the floor by my bag."

Anita moved over to pick it up.

"Don't cross his shadow!" The Doctor shouted. She nodded nervously and picked it up, handing it to The Doctor. "Thanks. Now, the rest of you, helmets back on and sealed up." He put the helmet on Proper Dave, sealing it on. "We'll need everything we've got."

Donna frowned, "But Doctor, we've haven't got any helmets."

"Yeah, but we're safe anyway." Zara smiled at her.

"How are we safe?"

Zara winced, "We're not. Sorry."

The Doctor smiled proudly at her, "That was just a clever lie to shut you up." He told Donna. "Professor, anything we can do with this suit?"

"What good are the damn suits?" Lux snapped. "Miss Evangelista was wearing a suit. There was nothing left."

"We can increase the mesh density." River said. "Dial it up to 400%. Make it a tougher meal."

The Doctor nodded, throwing Zara the sonic. She caught it one handed and used it on Proper Dave's suit.

"800%." She nodded. "Pass it on." She turned and held it out to River.

"Gotcha!" River grinned, holding up a similar sonic with extra settings.

The Doctor moved over next to Zara, "What's that?" He asked as he and Zara frowned at it.

"It's a screwdriver."

"It's sonic." Zara said, raising an eyebrow at her.

"Yeah, I know." River grinned. "Snap!" She turned and soniced everyone elses suits.

The Doctor grabbed Zara and Donna's hands, "With me! Come on!" He pulled the two of them into the shop and up to a teleport with three pads next to the controls.

"What are we doing?" Donna asked. "We shopping? Is it a good time to shop?"

The Doctor pushed her towards the teleport pad, "No talking, just moving. Try it. Right. Stand there in the middle." Donna nodded, moving onto the middle pad. "It's a teleport. Stand in the middle." He moved over to the controls, fiddling with them. "Zar, get on." Zara raised an eyebrow at him as he focused on the controls. "Can't send the others, the TARDIS won't recognize them."

"What're you doing?"

"You don't have a suit, you're not safe!"

"You don't have a suit, so you're in as much danger as I am and I'm not leaving you!"

"Donna! Let me explain..." He pressed a button on the controls and Donna disappeared. "That's how you do it!" He grinned before his face suddenly dropped, noticing Zara was still standing in front of him. "Zar!" He ran round and grabbed her hands. "You need to go, it's not safe!"

"ZARA, DOCTOR!" River called from the other room.

Zara squeezed The Doctor's hand and pulled him back into the room. They looked over at Proper Dave with a frown to find Proper Dave with only one shadow.

"Where did it go?" The Doctor asked.

"It's just gone." Proper Dave replied. "I looked 'round, one shadow. See?"

"Does this mean we can leave?" River asked. "I don't want to hang around here."

"I don't know why we're still here." Lux said. "We can leave him, can't we? I mean, no offence..."

"Shut up, Mr Lux."

"Did you feel anything, like an energy transfer?" Zara asked, looking at him carefully. "Anything at all?"

"No." Proper Dave replied. "No, but look, i-it's gone." He began to turn around.

"Stop there." The Doctor ordered. "Stop, stop, stop there. Stop moving!" Proper Dave suddenly stopped. "They're never just gone, and they never give up." He got down on his knees, testing the shadows with the sonic. "Well, this one's benign."

"Hey, who turned out the lights?"

The Doctor looked up at him, "No one, they're fine."

"No, seriously, turn them back on."

River frowned, "They are on."

"I can't see a ruddy thing."

The Doctor stood up, reaching back and grabbing Zara's hand, "Dave, turn around."

"What's going on? Why can't I see? Is the power gone? Are we safe here?"

"Dave, I want you to stay still, absolutely still." Proper Dave suddenly stiffened, making The Doctor squeeze Zara's hand. "Dave-Dave? Dave, can you hear me? You all right? Talk to me, Dave."

"I'm fine. I'm okay. I'm-I'm fine."

"I want you to stay still, absolutely still."

"I'm fine. I'm okay. I'm-I'm fine. I can't... Why can't I? I-I can't... Why can't I? I-I can't... Why can't I? I..." The lights on his communicator began to blink.

"He's gone." River said sadly. "He's ghosting."

"Then why is he still standing?" Lux asked.

"Hey, who turned out the lights?" Proper Dave stammered. "Hey, who turned out the lights?"

The Doctor moved closer to Proper Dave, still holding onto Zara's hand.

"Doctor, don't." River said warningly.

"Dave, can you hear me?" The Doctor asked.

"Hey, who turned out the lights?" Proper Dave snapped. His hands suddenly shot out and grabbed The Doctor round the neck, making The Doctor let go of Zara's hand. The Doctor glanced up at Proper Dave's helmet, a skeleton peering through the visor.

Zara stared in horror, "Theta!" She breathed.

"Hey, who turned out the lights? Hey, who turned out the lights?"

"Excuse me!" River called, reaching over and using her sonic on the port of the suit, making Proper Dave let go of The Doctor.

The Doctor scrambled backwards, "Back from it!" He shouted, reaching round Zara's waist and pulling her back. "Get back, right back!"

Proper Dave stumbled towards them awkwardly.

"Doesn't move very fast, does it?" River asked.

"It's a swarm in a suit." Zara breathed, squeezing The Doctor's arms. "But it's learning."

Four shadows began to spread out from its feet, getting towards them further and further.

"What do we do?" Lux panicked. "What do we do?"

"See that wall behind you?" River asked. "Duck!" She turned and pulled a sonic blaster out of her holster and used it on the wall, making a squared opening.

"Squareness gun!" The Doctor cheered.

"Everybody out!" River ordered. "Go, go, go! Move it! Move, move! Move it! Move, move!" Everyone ran out of the room and into an aisle of shelves. "You said not every shadow-"

"But any shadow."

They all looked round nervously when Proper Dave appeared at the opening.

"Hey, who turned out the lights?" He shouted.

"Run!" River shouted, grabbing The Doctor and Zara's hands, the three of them running down the narrow aisle between the shelves.

...

The Doctor used the sonic on an overhead lamp as the others stood around, trying to catch their breath.

"Trying to boost the power." The Doctor muttered. "Light doesn't stop them, but it slows them down."

"So what's the plan?" River asked. "Do we have a plan?" She took out her sonic, using it on the light, making it brighter.

"Your screwdriver..." He stepped down, standing next to Zara. "Look exactly like mine."

"Yeah. You gave it to me."

"I don't give my screwdriver to anyone except for Zara."

River smirked, "Or Martha Jones." The Doctor and Zara shared a nervous glance for a moment. "I'm not anyone."

"Who are you?"

"What's the plan?"

Zara sighed, "We teleported Donna back to the TARDIS. If we don't get back there in under five hours, Emergency Programme One will activate."

"Take her home, yeah." She turned to the others. "We need to get a shift on!"

Zara grabbed The Doctor's wrist, pulling the sonic up to her gaze, "She's not there." She breathed.

The Doctor's eyes widened, "We should have received a signal. The console signals me if there's a teleport breach."

"Maybe the coordinates have slipped." River shrugged. "The equipment here is ancient."

The Doctor ran over to a node, "Donna Noble. There's a Donna Noble somewhere in this library. Do you have the software to locate her?"

The Node swivelled round, revealing Donna's face.

"Donna Noble has left The Library." The Node announced in a monotone voice. "Donna Noble has been saved."

Zara gasped, horrified, "Donna."

"Donna Noble has left The Library. Donna Noble has been saved."

"How can it be Donna?" River asked, stunned. "How is that possible?"

"Donna Noble has left The Library. Donna Noble has been saved."

"Oh, Donna." The Doctor whispered.

"Donna Noble has left The Library."

Suddenly, Proper Dave appeared at the end of the aisle, "Hey, who turned out the lights?" He called.

"Doctor, Zara!" River called.

The Doctor and Zara stared at Donna's face as the Node repeated itself, River and the others running over towards them.

"Hey, who turned out the lights?"

"Donna Noble has left The Library." The Node announced. "Donna Noble has been saved."

"Zar, Doctor, we've got to go now!" River snapped, grabbing both their arms and pulling them along.

Proper Dave stumbled down the aisle, "Hey, who turned out the lights?"

"Donna Noble has left The Library." The Node announced. "Donna Noble has been saved."

"Hey, who turned out the lights?"

The group ran down the aisles away from Proper Dave, reaching a dead end.

"Zara, Doctor, what are we going to do?" River asked, Proper Dave reaching the other end.

"Hey, who turned out the lights?"

"Donna Noble has left The Library." The Node announced. "Donna Noble has been saved."