Later that night, after Jack had left the hub to clear his head, Rose found herself back in the lab and working on the transporter once more. It wasn't until her phone rang that she discovered Owen had returned to the hub.

"Rose, I called Jack but... well, I found something I think you're both gonna wanna see," he said when she answered and Rose frowned.

"Owen? I'm in the lab," she replied, and a moment later the doctor's head appeared around the corner of her doorway. He rolled his eyes and snapped his phone shut, ending the call sharply.

"Do you know what this is yet?" He demanded, indicating the device on her table but Rose didn't answer, shooting back a question of her own instead.

"Why?"

"Because whatever it belongs to has been ripping out people's hearts ever since it arrived," Owen explained, and Rose could almost feel the blood draining from her face.

"You said you called Jack?" She asked, and Owen nodded.

"He said he'd be here shortly," the doctor said and Rose bit her lip, before nodding.

"All right. Give me a shout when he gets here?" She asked, and Owen nodded, before heading back to his computer to organize whatever files he'd found.

Rose turned her attention back to the transporter, and let her mind go back over the plan she and Jack had thrown together earlier in the evening. They had a plan, sure, it just wasn't a very good plan, or very well developed, and Rose could see a thousand ways it might go wrong.

It was, however, the only plan they had.

A quick test of Rose's theory, that the species who had travelled with the transporter was telepathic, proved that, with a little effort and a huge headache, Rose could access the settings and with Jack's knowledge of space-time coordinates, they had reconfigured its programmed landing location.

She'd hoped that they wouldn't need to use the transporter as the weapon they'd turned it into, but if this creature had been ripping out hearts for nearly two hundred years, then she doubted it would be willing to sit and have a rational discussion about its crimes.

At best, it was going to be scared and desperate. At worst, brazen and dangerous. Rose just hoped that it wasn't Tosh caught in the middle.

Jack had only needed to take a brief glance over the files Owen had collected before he called in Ianto and Gwen, barely waiting for them to settle into their seats in the conference room before he launched into an explanation.

He gave them a brief rundown of the situation, explaining that they believed Tosh was being manipulated by the very same alien that had been tearing out hearts and could be in serious danger.

Rose had suggested that they gloss over the potential that Tosh had been privy to her teammates surface thoughts for several days, and Jack had agreed but before the Captain had been able to fully explain the plan he and Rose had cobbled together earlier in the evening, Ianto had informed them all that Tosh was entering the hub and she wasn't alone.

"Get out of sight," Jack ordered, "we wait to see what they're here for."

The team scattered at his order, and Rose had to force down an inappropriate grin as the lights flickered off and she got the sudden mental image of them all jumping out and shouting surprise.

Now wasn't the time, she berated herself, and instead, she focussed on strengthening her mental shields.

She tucked herself behind a solid portion of the rail on the catwalk above the lab, and Jack appeared beside her silently a few moments later, the transporter in his hands, just as the main vault-like door rolled open.

The alert triggered exactly as it was supposed to, the alarm blaring and lights flashing due to its night-time activation, but when it was quickly silenced Rose knew Tosh had shut it down in a futile attempt at remaining undetected.

"Can you trigger the transporter if we need it?" Jack whispered by her ear, and Rose nodded, before they both fell silent, listening to Tosh and her friend step ever deeper into Torchwood.

"In Xanadu did Kubla Khan, a stately pleasure dome decree. Where Alph, the sacred river ran, through caverns measureless to man, down to a sunless sea... So, where is it, lover?" Came the delicate sing-song voice of the stranger and Rose was careful to keep her thoughts locked down tight, hoping that the rest of the team were out of this being's telepathic range.

Jack not having time to explain their plan might work in their favour, Rose thought a moment later, when she realised that the Torchwood Team's unprotected minds might well have ended up being their downfall.

"Stay here. If Rose has finished working on it, then Jack, my boss, must have it," Tosh explained, and they could hear her boots against the metal walkways suddenly come to a stop.

"Be quick," the other woman all but purred, "I've a long journey ahead of me. I might need something to eat before I go."

The subtle threat to Tosh's life was all it took to snap Jack's control, and Rose cursed under her breath at his recklessness.

"This what you're looking for?" He called out as he stood, staring down at the pair with a grin.

"Jack..." Tosh breathed, and Rose didn't know if she was scared or upset that he was holding the teleporter.

"A friend of mine, let's call him Vincent, that was his name after all," Jack told them as he started to move along the catwalk towards the stairs, and Rose recognised the beginning of a story that was designed to distract and buy time.

She knew he'd picked the habit up from the Doctor and the familiarity of the technique brought a smile to her face, despite her concern for Tosh and Jack, and even the alien.

"Vincent was a regular guy. Had a girlfriend, liked his sports, liked a beer. Then he starts acting a little... strange. A little distracted," Jack continued, keeping his steps slow and measured, with the transporter grasped firmly in both hands.

"Suddenly he disappears for a couple of months. He comes back, and we've got to start calling him Vanessa!" He exclaimed, finally reaching the stairs and moving down them smoothly, barely breaking the flow of his story.

"Since then I've always been a little nervous when a friend behaves out of character," he told both Tosh and the stranger, his voice turning from cheerful to firm in the space of a sentence.

Rose leant around her barricade slightly, just enough to keep an eye on Jack as he faced off with the alien who stood in the centre of the hub in the form of a beautiful young woman, all smiles and blonde hair.

Rose admired the way Jack had managed to remain unthreatening, and still broadcast the fact that he didn't trust the stranger amongst them as he leant forward slightly, holding her gaze.

"I'm sorry, we haven't been introduced. Jack Harkness. My guess is you're not from around these parts ," he drawled, forcing his words to carry a strong southern US drawl, that under other circumstances would have made Rose laugh aloud, and she made a mental note to get her friend to repeat the accent at a later date.

"Now this?" He continued, laying the trap for their guest, even as Rose hoped she wouldn't take it, "Huh! This is incredible! You know what it is?" He asked, and Rose watched him shift just slightly, enough to be clear he was addressing Tosh.

"It's a transporter," Tosh answered, "Mary was a political prisoner. She was exiled here. Look, Jack—"

If Rose hadn't seen the hundreds of victims with their hearts ripped out of their chests, she'd have wanted to help this woman as well, she admitted to herself and Rose let her eyes drop closed for a moment with a resigned sigh.

If the deaths were necessary for survival, and if the woman showed remorse for that necessity they could still help her. It all fell on the woman now, and Rose was keeping her fingers crossed that her hopes weren't misplaced.

"You've got half of it right," Jack cut Tosh off firmly. He had managed to shift closer as they spoke and now stood only a few feet back from both women, both of them turning as he moved and they now stood with their back's to Rose's position.

Taking advantage of their distraction, Rose carefully stood and crept along the catwalk, her movements glacial so that the rattle of metal didn't alert them to her presence, all the while Jack continued to illuminate their friend and challenge Mary into explaining herself.

"Mary, it is Mary, isn't it? You want to tell her the really interesting bit?" Jack asked lightly, "No? Chatty, isn't she? I don't know how you got a word in edgeways, Tosh," Jack drawled sarcastically before continuing.

"It's a two man transporter, or whatever you people may be. You might be squids, for all I know. A two squid transporter. Room for one prisoner, and one guard," Jack taunted, latching onto the one piece of information Tosh had provided that they hadn't already known, and Rose winced as she quickly put the pieces together.

Where was the guard?

"Want to tell us what happened to your guard, Mary?" Jack prompted, and for the first time since he had revealed himself, Mary spoke.

"I killed him," she announced easily, "but I was disturbed. A woman came, and I was in no hurry to return home to be executed. I knew I would need a body on this primitive planet to blend in, so took hers," Mary explained.

Rose still couldn't see Tosh's face, but from the way Tosh grasped at the strap of her bag, and wavered just half a step away from Mary, Rose knew that the woman hadn't known.

The vault door suddenly began to close, and Rose silently thanked Ianto for hitting the remote. Slowly, the rest of the team revealed themselves to Tosh and Mary, and Rose gave up her slow, quiet movements, descending the same steps Jack had gone down and moving to stand just behind the Captain as the rest of the team spread out around the hub cautiously.

Clearly hearing Mary so casually admit to the murder of her guard, and the possession of a human body had made them all decide not to leave Jack or Tosh alone with the woman.

Mary glanced around at them all but overall seemed unconcerned with their presence, merely continuing her tale.

"Then another came. A soldier. He tried to shoot me, so I plunged my new human hand into his chest and plucked out his heart," Mary announced cheerfully and Owen shook his head, anger written in every line of his face.

"And that's what you've been doing ever since," he accused and Mary didn't deny it, agreeing easily.

"This form needs to be fed."

"All those punctures were all about the side of a fist. My God, all those people. You killed all those people..." Owen spluttered, as though unable to quite comprehend the sheer number of deaths this woman had caused.

What broke Rose's heart wasn't just the deaths, but the way in which Mary was showing no regret and no remorse for her actions.

Rose could have forgiven her if it had been a choice between killing people or death. Something she'd wished to avoid doing but couldn't. Something she regretted, but the grin across her soft human features was cold and Rose shivered when Mary continued her story once more.

"I fled before any more soldiers came. I had so much to explore, and how I loved this body!" She exclaimed with a light laugh, stalking away from where she'd been cornered, moving closer to the lab Rose had spent the last few days working in, and was swiftly followed by Tosh and Jack.

"So soft... So wicked... The power such a body has in his world," she purred in delight, and Rose watched Tosh flush and duck her head.

Rose moved around the room as Mary continued, trapping the woman between herself and Owen, with Tosh and Jack on the walkway over the water from the fountain that the alien had just stepped off.

As she began to bring her story to its end, Mary began pacing restlessly, like a tiger in a case, and Rose could feel her frame tensing in response.

The woman was too relaxed considering her position, which in Rose's experience, meant the woman had a plan.

"Within a few years the forest had gone, the transporter was safely buried under the spread of the city, but I didn't care. As I said, I wasn't in any hurry to get home. The more time that passed, the more likely it was they will have forgotten about me and—"

"And you've been killing ever since," Rose cut her off, drawing the woman's eyes to her and making Jack shift slightly in concern.

"I knew there might come a time when my situation here became complicated," Mary said, her dark eyes locked on Rose's and the two women glared at each other for a long moment, before Mary turned back to Tosh, Jack and the transporter in his hands "but I was safe as long as I knew where the transporter was."

"And then it was uncovered," Jack added, but Mary wasn't finished.

"As soon as the air touched its surface, I could feel it. So I found my Toshiko. My beautiful Toshiko..."

Rose watched Owen tense, but before she could do or say anything to stop his movements, Tosh snapped her head around to stare at him, mouth open to shout a warning that, Rose noticed, Mary didn't seem to need.

"Owen, no!"

A blur of movement and gaseous energy later and Mary had swiped up one of the blade-like tools from Rose's lab table and moved back to Tosh's side, holding her arm in one hand and pressing the blade to the woman's throat.

Rose managed one step towards them both a growl of frustration escaping her, but she forced herself to still, not willing to risk Tosh.

"Let her go, Mary! Let her go!" Jack shouted, and Rose could hear Owen cursing his own mistake.

"Toshiko, tell them to give me the transporter," Mary said calmly, and Rose's hands curled into fists when her friend started crying.

"I can't, Mary."

"You," Mary said suddenly, nodding at Owen, "I'll exchange Toshiko for that one," another nod at Gwen and Rose narrowed her eyes as she tried to figure out what Mary was playing at.

"Just... put the knife down," Owen tried, and Mary grinned.

"Did you hear him? He didn't want to, did he?" Mary cooed into Tosh's ear, and everything fell into place for Rose.

Surface thoughts.

The fleeting things that pop into your head. The frustration fuelled hatred that you'd never really mean or act on. The shallow and superficial desires that are never spoken, because you're ashamed of them. The preference of one friend over another, the preference you never show because you know in your heart that you'd never swap either of them.

Surface thoughts were cold and cruel, without the deeper emotions and motivations behind them to clarify their existence, and surface thoughts were all that Tosh could hear.

If she believed that surface thoughts were true emotions and motivations, then Mary might be able to get Tosh to help her, and Rose wasn't going to let her friend be used like that.

"Please, don't," Tosh begged, and Rose took a deep, steadying breath.

"That's what they think of you. That's who you've been working with for all these years..."

Carefully, Rose lifted the protections on her mind and let Tosh into her head, wincing slightly as she finally understood what Jack had meant by the crawling sensation.

However Tosh was doing what she was doing, it wasn't a natural ability.

'Tosh' Rose whispered softly, hoping the quiet call would be missed by the alien holding her friend. 'It's not true, what she's saying. You're only seeing the surface thoughts. Fleeting thoughts, images, and emotions that mean nothing' she offered and slowly Tosh's breathing was calming.

Mary's pleased smile seemed to indicate that she thought it was her cooed words of affection, but Tosh's dark eyes were staring at Rose in shock and surprise.

"— It doesn't change the way I feel about you. We have a connection, Toshiko, Something real..." Mary purred, and Rose offered the technician a small smile.

'Trust me... Trust Jack... and I'll take you to a real pub quiz when this is all over,' Rose whispered, and Tosh loosened a watery laugh, despite the blade at her throat.

Her eyes flicked to Jack then, and Rose slammed her walls back into place.

With Mary's lack of remorse and Tosh's life on the line, she knew Jack would be implementing their plan and she moved, carefully, to stand beside him, slowing her pace and lifting her hands placatingly when Mary tightened her hold on Tosh.

"Okay, you want the transporter? We want Toshiko. I think that's a fair swap," Jack insisted, eyes bordering on frantic, and Mary smiled at him slowly.

"Keep the knife, and I'll give you the transporter myself," Jack offered, holding out the transporter temptingly and after only a moment's consideration, Mary took the offered opportunity.

Shoving Tosh away from her and into Ianto's arms, Mary grabbed hold of her ticket home, freezing when Jack didn't release his own hold and grinning at the Captain.

"You smell... different... to them," Mary said slowly, and Rose began creeping closer to the pair of them staying out of sight behind Jack's larger frame while he distracted the alien.

"That's nothing. It's when you compare teeth with a British guy that's when it's really scary," Jack flirted.

"What are you?" Mart asked him, curiosity written all over her face, and Rose used her fascination to slide a hand around Jack's waist and lay her palm against the device, linking her mind with the transporter's interface and hitting the activation switch.

"I don't know," Jack admitted quietly and Mary laughed, not noticing the vibrations running through the transporter.

"And you would have put me in a cage?" She asked before Rose stepped out from behind Jack, a hand pressed to her temple as she fought off a blinding headache and shook her head.

"We were never going to put you in a cage," she denied as the transporter activated, beeping loudly as the humming grew deeper and more audible.

Mary's smile vanished, and she glanced down at the device in her hands.

"What's happening?"

"Oh, that?" Jack asked lightly, letting go and backing away from Mary, casually slinging an arm around Rose's waist as he went and pulling her with him, while simultaneously offering her support as she swayed from the headache now raging through her skull.

"I reprogrammed it for you. It's set to enable—"

The transporter beeped once more before a loud clanging sound could be heard, and Mary was forced into her natural form, before being enveloped in the light now emitting from the device.

Quickly, the ball of light shot up, passing through the pavement above their heads and disappearing towards the coordinates that Rose and Jack had set mere hours earlier and Rose let her head fall to rest against Jack's shoulder, her eyes slipping closed.

"— Sort of now," Jack finished his previous sentence softly.

"What did she—? Has she gone home?" Rose heard Tosh ask, tears still in her voice and Rose winced and opened her eyes, bracing herself to tell Tosh, but Jack squeezed her waist and took the blame.

In the same way that Rose had fired the first shot when Lisa had stolen the body of the pizza delivery girl to guard Jack against Ianto's anger, Jack was doing the same thing for her now with a simple shake of his head.

"I reset the coordinates," he explained simply.

"Where to?"

"To the centre of the sun. It shouldn't be too hot, I mean, we sent her there at night and everything," he drawled. It was a poor attempt at humour, but then she could hear the anger and fear bubbling away just beneath the surface of his words.

"You killed her," Tosh muttered, the accusation clear in her voice, and it seemed to be the last straw for Jack.

"Yes!" He snapped, but Rose pressed her head against shoulder a little more, and he stilled. Tosh hadn't seen the hundreds of bodies yet. She'd not seen the files on hundreds of victims that Mary had left behind with their hearts torn out of their chests, and the lack of remorse over those deaths had clearly evaporated any kind of forgiveness Jack might have offered to the alien.

With that single word and Rose's gentle encouragement not to snarl out anything further, he carefully turned and guided her out of the main hub, getting her settled in a quiet room with some painkillers, and leaving the rest of the team behind.

Rose let Jack fuss, taking the tablets he gave her and waiting for the pounding in her brain to begin to recede before she opened her eyes, only to find the Captain sitting across from her quietly, a look of concern in his blue eyes.

"You should speak with Tosh," Rose began, her voice barely more than a whisper, "help her to understand."

Jack didn't answer her, just lowered his eyes and Rose sighed silently.

"Seriously, Jack. She loved Mary, and Mary used her. She used her emotions and her insecurities to manipulate her. The last thing someone needs after an experience like that is more judgement," Rose told him, barely smothering a wince as her memories of Jimmy Stone floated through her mind, and Jack frowned at her grimace.

"Hey, are you okay?" He asked quietly, and Rose offered the man a weak smile.

"I will be... and so will Tosh. Go and speak with her" she urged again and Jack huffed a sigh, but he couldn't quite smother the soft smile that her concern for their friend drew to his lips.

"Rest," he told her firmly, "let those painkillers do their job. I'll come and find you in a bit."

He rose to his feet and leant across the table to press a kiss to Rose's forehead, and Rose hummed a quiet agreement. She watched him pick up the files on Mary's victims off Owen's desk before he moved out of her line of sight, and Rose let her eyes fall closed once more, breathing out slowly as she waited for her mind to stop throbbing.

'Six hours' the Doctor thought with a grimace.

He should not have needed to sleep for six hours, and the fact that he had meant that the Tardis had been right and he'd desperately needed to rest.

The carefully neutral tone of the hum told him that she was concealing a certain amount of smugness at his conclusion, and he shot the time rotor a sullen glare in response.

But now, he was wide awake, and the Tardis could no longer distract him from the words of the oddly suspicious Professor Lazarus, and he impatiently tuned the Tardis monitor to the right date and time for the news broadcast that had been on Martha's TV.

Almost as soon as he'd woken up and gotten back into the console room, the Doctor had been looking into the Professor and his work.

Everything seemed fairly innocuous. Innocent, even, and nothing that the man seemed to be working on could really be described as 'changing what it meant to be human'.

All of which made the Doctor suspicious of the interview he'd witnessed at Martha's flat, which was why he'd decided he needed to see it again.

The Tardis tuned into the right signal, and once more the old professor stood in front of cameras and reporters, with Martha's sister just behind him, and made his confident declaration as the Doctor frowned back at him.

If Martha's sister worked for the Professor, maybe she knew what he was working on. He could ask Martha—

The Doctor's thoughts ground to a halt before he began to grin. An excuse not to be alone inside the Tardis was all he'd needed, and he flipped the handbrake, reversing their last dematerialization and darting to the doors of the Tardis.

"No, I'm sorry," he said as he swung his body out of the door and shook his head at a beaming Martha mere seconds after he'd left.

"Did he just say he was going to change what it means to be human?" The Doctor demanded, knowing exactly what the Professor had proclaimed and watched Martha struggle for a casual response to his sudden reappearance.

"Uh... yeah, I think so," she spluttered, and the Doctor stepped out of the Tardis again, pulling the doors closed behind him.

"Well, we can't have that. Fancy crashing his party?" He asked.

Martha's grin grew even wider as she nodded, and the Doctor beamed back.