Alec staggered to his feet. He was confused. All he knew was that he was jumping out a window in 2004 at one moment, and was suddenly somewhere else in the next. Where was he? He was in a cell, he knew that. But it wasn't a police cell. It was a white room, with golden spheres on the walls. His leg was numb, tightened by the chain around it. The room was cold, and in the centre of the large, empty room he felt exposed. "Hello?" Alec called. "Is anyone here?"

"Yes," a voice called.

Alec could see her, the girl that called, through a spherical hole in the wall. She was the same age as Alec, 14, and had wavy brown hair and blue eyes. "Hello," Alec stuttered. "Who are you? I'm Alec, Alec Parker."

"I'm Shannon, Shannon Taylor. Hello Alec," Shannon smiled.

"Where are we?" Alec asked.

"Not a clue," Shannon replied, "and if I did I would've tried to escape by now."

"Ok then, why are we here?"

"Good question! You are smart. Don't know that either. I was walking my dog and suddenly I was here. I miss that dog. I miss my mum as well. Where were you?"

"I was . . . In the middle of an important job."

"Anything to do with that crown?" Shannon asked, pointing to the crown which was at Alec's feet.

"Ah, right. I was kind of . . . Stealing it, basically. But for the right reasons."

"And what reason is that?"

"I know this sounds ridiculous, but I'm a child agent."

"After all I've been through, that's very believable. Actually . . . No, not really. I'm not that gullible."

"It's not any crown; it's one of the crown jewels. The crown was stolen in 2004 and was found a week later on eBay. All connections converged on Franco Olivier, and I was sent to get the crown back. The crown was being kept at Gloucester House, which was where my cousin's wedding reception was being held, as I had planned."

"EBay?" Shannon asked, raising an eyebrow.

"I know. That's modern theft for you."

"Seriously? I would've thought there'd be some sort of underground communicate system which leaks British artefacts into Hong Kong. Now that sounds like a James Bond story! What's next? Holograms on watches, tunnelling under America, invisible space ships? Along with teenage spies, let me guess?"

"Hey, the plan worked . . . Until I appeared here. I'm not sure how."

"Was there a white light?"

"Yes. That blinding light that seems to swallow you. You too, I'm guessing?"

"Yep," Shannon nodded. "I thought I'd stepped on a bomb or something, even if that does sound ridiculous."

Alec looked over himself - he was no longer in the suit he had worn at the party. Both he and Shannon were in grey boiler suits, like prisoners, in a way. "What happened to my clothes?"

"The staff took them. Sorry if that suit was expensive; it's probably been burnt."

"When did they take my clothes?"

"When you were asleep."

"Asleep?"

"You've been out cold for about two weeks now, maybe more or less, it's hard to tell in this place."

"Two weeks!" Alec gasped. "How long have you been here?"

"I don't know."

"Then estimate."

"Four months!" Shannon snapped. "Four months waiting in this room, on my own. It's cold at night. It's hot in these bloody clothes. There's nothing to do so I speak to whoever's in the cell next to me, but even then they'll be taken at some point or another. Four months of my life- wasted!"

"That's horrible," Alec gasped.

"Don't! Don't act like you know. You've only been here for two weeks, and you were asleep! Do you know what I did for those weeks? Nothing. Nothing but sit and watch you because there was nothing else. Does that sound like fun to you? No! It wasn't!"

There was a knock at the cell door as it swung open. Alec crawled to the edge of the room.

"Don't worry," Shannon whispered, obviously a little scared herself. "Shush. Stay quiet."

"Who is it?"

"Best behaviour Alec, or he'll punish you. But don't worry, it'll only be Mr Derbyshire."

The TARDIS landed with little grace, wheezing and groaning. Sasha staggered back to her feet after being flung to the floor, gasping in excitement. "I love your ship. Have we landed?"

"Yes," the Doctor replied, "it's 2004 at your cousin's wedding reception."

Sasha smiled, running out of the TARDIS doors. It had landed outside the large manor the reception was held at, in the cold and dark, watching as the party within. The party was in full swing, wild with colour and dancing relatives. The night was dark, lit faintly by the moon, and was cold. "Oh my God!" she gasped. "We've travelled in time! It's 2004. Look, over there, that's Auntie Agnes, and Uncle Donovan. Jesus! That's Meredith, our old neighbour; she had a stroke last year and died. She's still alive, she's still here!"

"Don't dwell on it," the Doctor advised, closing the TARDIS door behind him as he stepped onto the dance floor. "She's still dead."

"But, I suppose, no-one's ever dead. Not for you at least. You can go back in time and save anyone you want. Could we do it? Could we warn them not to go on the motorway at three pm on Saturday the 13th of March, or that eating anymore fast food will give them diabetes? Could we at least warn Meredith; I owe her everything?"

"No, Sasha, we can't. No matter how hard it is, you should never alter your own past, as it could have untold consequences in the future. This is your personal past we're in, so we can only watch. Don't change a single thing or everything could will wrong!"

"But she's not going to destroy the world, or because Prime Minister. She's just a sweet, kind woman. What's the harm in saving her?"

"Chaos theory, Sasha. On small change will become a domino line, and who knows what will happen at the end."

"So I can't even leave a leaflet in her car for a gym? That could be all it'll take."

"No!" the Doctor snapped. "I knew it was a risk bringing you here. Don't touch a thing! Don't speak or make eye contact. Take this as a serious warning."

"Ok, ok. I get the message. So this is like the butterfly? Step on my past and my future will change."

"Yes," the Doctor confirmed. "And don't be seen either. You should just blend in with the party, but don't interact with Alec or yourself."

"Ok." Sasha breathed to calm herself. "So, where do we go? Do we find Alec?"

"That'll be a good start," the Doctor said. "Can you remember where he went?"

"He said he went to the toilet, then the fire alarm went off. It was then that we realised he was missing."

"But there wasn't any fire?"

"No. Someone had set off an alarm on the fourth floor," Sasha remembered.

"How do we get to the fourth floor?" the Doctor asked.

"The steps over there."

The Doctor followed Sasha into the hall, where it was considerably warmer, then up the steps, taking them to the fourth floor, to the red carpets and the golden framed paintings. "Look, over here," the Doctor said, pointing at a black bag behind a plant pot.

"What is it?" Sasha asked.

"A bungee cord," the Doctor announced, opening the bag. "It's an MI5 bungee cord as well."

"Whose is it?"

"Who do you think?" the Doctor smiled. Footsteps approached. "Quick in here!" the Doctor decided, pulling Sasha into a small room on the corridor. The Doctor squinted through the crack in the door, watching a 14 year old boy open the bag behind the plant pot. "I can see him. I can see Alec."

"Move up! Let me see him!"

"Shush!" the Doctor whispered. "He can't know we're here."

"But . . ."

"No." The Doctor insisted.

Sasha squirmed, stuck face-to-face with the Doctor in what had appeared to be a cleaner's cupboard, standing in a slightly damp bucket.

"He's . . ." the Doctor trailed off.

"What's he doing?" Sasha persisted.

"Quick, look at this," the Doctor said, pulling Sasha out of the cupboard to watch Alec jump out of the window. The fire alarm wailed.

"What?" Sasha gasped, peering over the edge of the window as Alec was flung back into a window a floor below them. "He's not MI5?"

"Oh, he definitely is!" the Doctor smiled. "Now that is cool."

"Come on, Doctor. He landed on the third floor, let's go after him!" Sasha declared, grabbing the Doctor's arm and pulling him down the stairs.

"Stop it! That's my job! I do the arm grabbing!" the Doctor complained as they stumbled onto the third floor. "Which room? Did you see?"

"I'm not sure . . . No, it was this one!" Sasha realised, pointing at the room ahead of them.

"Go to the room beside it. We can't disturb what's going on," the Doctor said, heading into the room next to the one Sasha had suggested.

Sasha and the Doctor stumbled into the room. It was a bedroom, with a large red duvet and many ornaments. The Doctor opened a window and climbed out of it onto a ledge.

"Doctor, what are you doing?" Sasha called.

"Shush!" the Doctor whispered. "I'm trying to see what's going on."

The Doctor climbed as far out as he could, peering his head across to the next room. Carefully, he leaned out, not daring to peer down at the ground below. The Doctor steadied himself on the window ledge, grasping tightly. He watched as Alec broke the glass cabinet and took the crown, then as the three guards entered. A gasp escaped the Doctor as Alec fell from the window, but there was something else. A tall man with a bald head and a black suit stepped to the window and held a silver device in his hand. The bald man pressed a button on it. Suddenly, Alec's body faded out of existence in bright light. "Get me a camera!" the Doctor called. Sasha handed him her phone. Holding tightly, the Doctor steadied his hand, and captured the image of the bald man.

The two of them hurried to the TARDIS, not looking at any guests to avoid being caught there any longer. Sasha found it hard, too tempted to greet an old friend and grab a slice of cake, which she eventually did. Vanilla.

"Who was he?" Sasha asked, finishing the cake slice. "Who was that man with the silver thing?"

"I don't know; that's why I took the picture," the Doctor explained, before disassembling Sasha's phone to get to the memory card.

"Be careful, Doctor. I've got a good contract so don't break it!"

"Don't worry, I know what I'm doing," the Doctor said, accidentally snapping the screen into several pieces. "Ah, right," he sighed.

"Urgh!" Sasha groaned. "You're getting me a new phone, and a good one."

A little more carefully, the Doctor inserted the memory card into the TARDIS console and pulled the monitor towards himself. Up came the image of the man, along with a string of letters and numbers. "I'm searching for a man with this face." The monitor beeped and a second image appeared, a clearer image of the man.

"Who is it, Doctor?" Sasha asked curiously, stepping towards the monitor to get a closer look.

"Mr Anthony Derbyshire, from Earth in the 24th century. He's a trader. He owns a warehouse at the Liverpool Docks."

"He's taken Alec to the 24th century? Why?"

"I don't know," the Doctor sighed. "Let's find out!" he announced, throwing a lever as the TARDIS wheezed and disappeared from 2004.

"Hello, Mr Parker, I hope you are comfortable," Mr Derbyshire smiled, handing Alec a sandwich on a plate with salad on the side. The man was foul! His teeth were crooked and his breath was like a Victorian sewage system. His hands were as white as snow; Alec could feel the cold radiating off of him.

"Who are you?" Alec demanded.

"I'm Mr Derbyshire."

"I know your name, but who really are you?"

"I come from the 24th century. You are also in the 24th century at this moment," he explained, his voice cool and sinister.

"Where am I?" Alec asked, taking the sandwich but not eating it. "And what do you mean: 24th century? It doesn't make sense."

"You're in a cell, I thought you would've realised with such a high IQ. And this really is the 24th century, even though it may be hard to believe."

"Why am I here?"

"Ah, that is a little more complicated. I will explain, but not quite yet," Mr Derbyshire grinned, heading back out the door.

"Has he told you anything?" Alec asked Shannon once Mr Derbyshire had gone.

"Not a word," Shannon sighed. "We're not the only ones here, you know. There are hundreds of children in this place. Sam used to be in the very cell you're in now. He was nice, a little weird though."

"What happen to Sam?" Alec asked, worrying inside.

"He was taken one night. I've asked Mr Derbyshire but he didn't tell me anything."

"Has anyone ever got out?" Alec asked.

"Nope. I wouldn't bother trying."

"Now that is a lazy attitude. Come on. We're going to get out of here."

"And how are you going to do that?"

"Well, I bet no-one expected an MI5 agent," Alec smiled. From his trouser pocket he took a nail, and used it to pick at the lock which bound his leg to the wall. It worked! Alec freed himself and went straight to the door with the crown in his hand, as the lock snapped open.

"Where are you going?" Shannon called.

"I'm coming for you!" Alec replied, his face alight with happiness.

"You'd better," Shannon laughed.

Alec shut the cell door behind him and arrived at a long corridor. It was dark and damp, covered with golden spheres and hexagons. It was harder to get into Shannon's cell; the door had no handle or knob, and it wouldn't open.

"Alec?"

"I don't know how to open it," Alec gasped, confused and irritated by the conundrum. "How does Mr Derbyshire open it?"

"He just walks in," Shannon called from the other side of the door.

"Hold on, I'll try and catch a lock or something," Alec decided. He took the nail and scraped it along the edge of the door, trying to find a lock in it. He tried on the other side as well. It caught something. Alec pressed hard against it, waiting for it to snap. There was a crushing sound from within the door, and it rolled upwards. As the door reached the top, a siren wailed down the corridor, and a light glowed a brilliant red.

"Hurry!" Shannon panicked.

Alec hurried beside her, picking the lock on her leg open. Alec grabbed Shannon and pulled her from the floor of her cell. A darkened silhouette appeared on the corridor wall, growing larger as it moved ever closer. The two of them ran, as fast as they could, like bullets down the corridor in the opposite direction of the approaching silhouette.

The TARDIS landed. Sasha stepped out into a dark room, a room full of levers and screens and controls. There was a glimmer of green light, but nothing else. She was scared, but she didn't show it. "Doctor?" she called. "Is he here? Will Alec be here?"

"He should be," the Doctor said, stepping beside Sasha, closing the TARDIS door behind him. "This is Earth in the 24th century. We're at an old storage base, but I suspect it's being used for other purposes now," he added, inspecting the controls and monitors.

"Why here?" Sasha asked. "Of all the places to take Alec, why here? When he first went missing, everyone thought that he was a runaway; that he was hiding something. The police, after a month or two, suspected that he was dead, but our family still believed that he was alive. If I could go back and prove everybody wrong, I would do. I set up a blog, asked for people to help me, but I only got more people crying at me and sharing there sympathy. What does it help? What does it help to cry when you don't do anything to look? But I'm right! I always knew I was! Alec is alive and that's all that matters."

"Shut up a moment," the Doctor groaned.

"I'm sorry? Do you not have any social skills?" Sasha remarked, taken aback by the Doctor's rudeness.

"I'm trying to think. I wasn't aware I needed social skills for that."

"These friends of yours, the ones you travel with, why do they leave you? Is it because you're always this rude to them. All this time travelling, is it all just an act? Behind all that mystery and adventure, is there just an old man that thinks the world revolves around him and his massive intellect?"

"Don't talk about my companions!" the Doctor snapped, a tear building in his eye. "I can't help it that they go; I don't want them to. And yes, maybe I am just an act, but it's an act that saves lives, and it saves people. This is what I do, Sasha! I travel in time to save anyone I can, and I take companions with me. Do you know why? Because I'm lonely! I can't help it that I grow old and miserable; doesn't everybody else at some point? I'm not perfect. I'm not a hero. I'm just someone that tries their best to save who they can because I can't do anything else! This, Sasha, is what I always do. I save people. When I can't save people, especially the people I love, it hurts. It hurts so much that I give up on the universe, I turn my back to it because, in my eyes, it's failed me. But I always give in. This is me giving in. One day, this will come to an end, and I'll be miserable again. I don't to ever have to feel this pain, but I always give in to it. And I've done it again!"

Sasha rushed over to the Doctor, immediately saddened, and holding his limp hand in hers. "I'm sorry, Doctor," she apologised. "But it don't understand – this will end. What is this?"

"You and me, in the TARDIS," the Doctor sighed. "I will always give in to an adventure," the Doctor smiled, as wide and humble as possible, holding a silver key in his hand for Sasha to see. "This adventure with you and me. Will you take part in it? One chance – choose well."

Sasha smiled. "You're asking me to travel with you, like all those companions of yours. Yes. Yes, of course I will," she grinned, glowing with happiness.

"Then enjoy it. Enjoy every moment!" the Doctor smiled, wrapping the TARDIS key in Sasha's hand. "Welcome to the TARDIS, Officer Parker."