Back at the lab, Nick called Warrick over to his computer. "Look at this," he said. "All the other surveillance footage is saved with date and time. Except for this." He clicked on an icon, which bore the name, "DoctorVisit9." Warrick studied the filename.

"Is it usual for the prison staff to refer to their prisoners by their nicknames?" he asked.

Nick shrugged. "No," he said. "And before you ask, there aren't eight other visits on file. As far as I can see, he only got the one visitor, about three days after he was incarcerated. After that, apparently, he wasn't allowed to talk to anyone else."

Warrick frowned. "Okay, so something in here made them decide he was dangerous. What happened?"

Nick opened up the file. "Take a look and see for yourself," he said.

The visitor was tall, about ten years older than the Doctor, with big ears and no hair. He sat propped back on the chair, his arms folded, wearing a black leather jacket. On the other side of the glass, the Doctor walked in, looking very serious. He didn't have the same emaciated or sickly look he'd had by the time he died, but he certainly wasn't cheery or bursting with energy. He picked up the phone on his side of the glass, and the visitor mirrored the gesture.

"So," said the visitor, "you're the latest model." The visitor had a sharp, northern English accent, and a loud, brash voice. He leaned forward and squinted. "Not bad. A bit tall. Still not ginger."

"The ears are an improvement," said the Doctor.

The visitor just touched his ears and gave a big grin. "Well, I'm gonna assume you called me here for some reason and not just to cause a temporal paradox. Contact?"

The Doctor looked directly into the camera, then back to his visitor, and shook his head. "They know who I am," he said in a low voice. "I don't know how much they know, but I'm hoping they don't know who you are." He paused. "Where's Rose?"

"Asleep," said the visitor. "Back…" he looked over at the camera, just the same way the other one had, and said, "home."

The Doctor nodded. "Look, three nights ago, there was a break-in. Middle of the night. Nothing was taken and nothing was disturbed… except for one yale key."

"Ah," said the visitor. "And you're hoping…?"

"Exactly," said the Doctor.

For a moment the two said nothing, just looking at one another as if daring the other to speak. Finally, the visitor gave in. "And that's all you're going to give me. Just a date and a time. What year is this, anyways?"

"2003," said the Doctor.

"Right," the visitor replied. "And that's all. No extra information. No security rundowns. No guard shifts, or prison schedules, or anything useful? I mean, come on. You've been in here three days? Don't tell me you've just been sitting around here twiddling your thumbs."

The Doctor raised an eyebrow. The visitor sighed.

"Just the stuff you learned since you got here, you dolt," he said. "Not from memory. And don't you give me that look. I'm not the one constantly trying to destroy causality. I've got Rose and her little boyfriends to do that for me."

The Doctor gave a tired smile. "Adam?"

"I swear, that's the last time I let her drag those pretty boys into the…" he stopped, looked back to the camera, then back at the Doctor. "Anyways."

The Doctor began talking a mile a minute, carefully outlining the security system, the prison routines, the guard shifts, and everything else needed for a well done heist. "Just you," added the Doctor. "I don't want to bring Rose into any of this."

"Just me, no Rose," agreed the visitor. "Got it."

"And don't try to hide the key around the prison or leave it for me to find later on," said the Doctor. "I just want that key out of this time zone as fast as possible. I have another way in, but it only works for me. I think it's better that way."

"Fine," said the visitor. "Is that all?"

The Doctor faltered. Then he whispered, "Tell Rose…" he stopped, and looked at the other man.

The man across the glass gave the Doctor a hard look. "I can't," he said.

The Doctor looked down. "I know."

"Not just for the sake of causality," added the visitor. He hesitated. "For Rose. I can't." He paused looking off in the distance for a moment, then back at the Doctor. "We told Charley," he said, so quiet that the microphones almost didn't pick it up.

"Yes," said the Doctor, and his voice was so sad, and lost, for a moment he sounded like a little boy. "We told Charley."

The Doctor and the visitor just looked at each other for another moment, and then got up as if to leave. Before he got far, however, the visitor leaned over and picked up the phone, a wide grin on his face. The Doctor picked up his receiver.

"Oh, and Doctor?" said the visitor with a cheeky grin. "They do say that talking to yourself is the first sign of madness!"

The Doctor started yelling incoherently at the other man as the visitor dropped the receiver and strode out of the room. The Doctor just looked after him, hung up the receiver, and muttered something that sounded like, "well, that's always embarrassing."

Nick Stokes looked at Warrick expectantly. Warrick examined the empty screen. "That…"

"Yeah," said Nick.

"They…"

"I know," said Nick.

"That's impossible," Warrick finally managed.

"Yep."

"They just planned a heist," said Warrick, "that took place three days before the conversation took place." He turned back to Nick. "The man—John Smith, the Doctor, whatever he's called—he said that they knew who he was, but they didn't know who the other guy was."

"Yeah, I noticed that, too," said Nick. "The visitor gave his name as Dr James McCrimmon."

"And there's no such person?" Warrick asked.

"Oh, there was," said Nick. "He died in 1746 in Scotland."

"So, not our guy," said Warrick.

"Nope," replied Nick.

Warrick paused a moment. "Hang on," he said. "Did you say his name was Doctor McCrimmon?"

Nick's eyes widened, as he realized where Warrick was heading. He dug out the copy of the prisoner file that Sara had found. He pointed at the familiar face on the page. "I knew he looked familiar, but I couldn't place him." Nick looked at all the other pictures. "So, you think this is some kind of gang of semi-professionals who call themselves Doctor?"

"Yeah, probably not," said Warrick. He pointed to the second picture, of an old man in a velvet coat. "That picture looks like it was taken in the early seventies," he said. "And he's maybe sixty years old. There's no way he's still around."

"His picture is crossed out," Nick pointed out. "In fact, all these pictures are crossed out except the last two. The two in that video."

"The last two alive?" Warrick asked.

"Seems the most plausible answer," said Nick. Suddenly, he started. "Hang on a second." He turned the page, looked at the Doctor's Body Count. "They kept talking about someone named Rose, didn't they?" He tapped his finger on the page, where, in the warden's handwriting, was the name Rose Tyler. "Think it's the same person?"

"I'll bet it is," said Warrick.

Nick and Warrick looked at one another. "Check the database for a missing persons report," said Nick. "Rose Tyler. Three months ago she was still alive."

They both went off to their computers to search. Warrick found Rose Tyler about an hour later. He frowned. "She's not dead," he said to Nick.

"What?"

He clicked on the link. "English. Lives in London with her mother, Jackie Tyler. Not dead, not even missing."

Nick checked his watch. "Eight hour time difference. Call the number listed and ask for Rose Tyler. Give her a description of our vic, and his mysterious visitor. See what she knows."

Sara hesitated before she walked into Grissom's office. She had seen him enough to know his moods, and she could see when something wasn't right. He was playing one of the cassette tapes they had picked up from the prison. It appeared that at first, he had been taking notes, but at some point he'd clearly given up the endeavor, as he now had his face buried in his hands. She gave a little knock on the door.

He looked up, stopped the tape, but the moment Sara saw his face, she knew her supposition had been right. He looked nauseous, upset, and his eyes had a terrible, haunted look of pain. He gave her a forced smile and told her to come in.

"Are you all right?" she asked, sitting at his desk.

He shook his head, looking at the tapes. "I don't think he was being paranoid," said Grissom. He hesitated, then looked up at her. "I think he was tortured."

Sara didn't say anything. She just stared at Grissom. She could feel that terrible sense of guilt gnawing at her insides again, that little voice that told her, 'you sent him there. You sent him to that fate.'

"The tapes are for us," said Grissom. "He figured that out right at the very beginning. He keeps trying to provoke the other people in the room so that they'll hurt him on tape. Presumably to give us proof."

Sara looked down at her hands, where she held the paper that Grissom had requested. She put it on his desk. "I got that transcript you asked for," she said.

Grissom gave her another sad smile. He took the transcript from her and examined it, his brow furrowing. Then he sighed. "Yes, that's pretty much what I thought." He looked at Sara. "As I recall, your assessment of our Dr Smith was…"

"Hang on," said Sara. "Doctor?"

Grissom gave a small shrug. "I don't know what his name really is," he said. "But the 'Doctor' part at least stays constant. Especially when Dr Bradshaw loses his temper. Then he just skips the pseudonym all together and merely addresses the vic as Doctor."

"Okay," said Sara. "I think I understand that."

Grissom nodded. "As I was saying, your assessment of Dr Smith appeared to be that he was criminally insane, is that correct?"

"That's what I thought," Sara said. She hesitated. "Why?"

Grissom ignored her, continuing on his train of thought. "It also appears that you thought that you were the one interrogating Dr Smith."

Now Sara really did pause. She examined Grissom's face, for some indication of where this could possibly be headed. "Are… yes, yes, I did." She cleared her throat. "I mean, I was. Definitely. I remember."

"Well," said Grissom, putting the transcript back down on his desk. "I'm sorry to be the one to tell you this, but you didn't."

"I'm sorry?"

"You weren't the one interrogating him," said Grissom, indicating the transcript. "He was the one interrogating you."

"That can't be right." Sara grabbed the transcript back and started skimming over the text. She couldn't see it. As far as she could tell, she had been asking Dr Smith logical, straightforward questions, and he had replied with complete jibberish.

Grissom ejected the tape he had been listening to, selected another one, and put it in the player. "At the time, I didn't notice," he said, "because every time he tested you, you gave him the right answers. It was only when I heard someone giving him the wrong answers that the technique became obvious." He looked at her. "Verity was right. That whole crazy rambling thing was all an act. The man wasn't insane, Sara. He was acting insane to get information."

Grissom played the recording.

Sara could hear a deep voice with a Midwestern accent introducing himself as Dr Bradshaw. He gave the date and time and explained that this was John Smith's first therapy session. He then cleared his throat, and continued.

"John Smith, how are you feeling?"

The answer was given in a cheerful British accent, the same voice Sara remembered from the last time that she had heard it. "Oh, I'm just peachy! Peaches and cream, as they say. Or should it be apple pies and cricket, this being America and all. Love your cricket, don't you."

Sara looked back at Grissom as if to say, "See? Crazy." Grissom pointed to her transcript, where she read nearly the same thing.

JS: But all you Americans think of is cricket and apple pie.

Sara: Baseball.

JS: I'm sorry?

Sara: Baseball. We don't play Cricket.

She heard Dr Bradshaw's voice over the tape. "I heard you had a panic attack in the cafeteria. Do you believe that we are trying to kill you?"

Sara paused the tape. "Wait a minute, wait a minute," she said. "That just… I mean…"

"As I said," Grissom told her. "You got the answer right. Apparently, Dr Bradshaw got it wrong."

"But how can anyone not know that?" asked Sara. "I mean, he must have just been humoring Smith."

Grissom rewound the tape a little, and pressed play again.

"Do you believe we are trying to kill you?" asked Dr Bradshaw.

"Oh, certainly not," chirped the British voice. "Well, perhaps. A bit. Maybe. I'm actually rather under the impression that you intended to threaten me."

"What leads you to that conclusion?" asked Dr Bradshaw.

"Well," said the Englishman. "There's the fact that you seem to have dosed all of my food and water with a substance that I personally find highly poisonous. Then there's the fact that every time I set foot anywhere in this prison, the cameras mysteriously malfunction. Oh, and I suppose the most obvious thing, which I'm assuming you failed to mention for a reason, is the fact that as I'm speaking to you, I appear to be surrounded by five armed guards pointing loaded rifles at my head. I'm assuming they are loaded? No blanks?" He paused a moment. "Really, I mean, I know I have a reputation and all, but I hardly think I'm the one being paranoid here."

"And what reputation do you believe you have, Doctor?"

The British voice took in a sharp breath. "Well, I am an insufferable namedropper. There's nothing quite like dropping in on famous historical figures and having tea with them—well, not tea, I guess. Threw that into the Boston Harbor in 1263. But you get the point. Had a great discussion about tea with Thomas Jefferson while he crossed the Delaware. You remember learning that in school? I think all Americans learn about that in school."

"Of course," said Dr Bradshaw, "you know you weren't really at the Boston Tea Party. As you said, it took place in 1263."

Grissom paused the tape this time. "Do you see what I mean?"

Sara was beginning to understand. She looked at her own transcript, where the obnoxious British man had informed her that he had been present at the signing of the declaration of independence in 1764. She looked back up at Grissom. "It's a test," she said.

"Exactly," said Grissom. "As far as I can tell, he's trying to work out if you are the person you claim to be. And it appears that Dr Bradshaw isn't really Dr Bradshaw."

"That's what he meant on those tapes we found throughout the prison," said Sara. "He said not to trust anyone. That people weren't what they seemed."

Grissom fast-forwarded through the tape, pressing play and then skipping again to try and find his place. When he had targeted the next section he wished to play, he gestured for Sara to listen, and started the tape again.

"Of course," chimed the British voice, "haven't been Merlin yet. Still got Excaliber somewhere in my piles of junk—I'm hoping that one day I'll pop my head out and find a medieval English countryside instead of coming face-to-face with an Harpinson Seventeen."

"Do you have some sort of fascination with musical instruments?" asked Dr Bradshaw.

"You know," said the British voice, but he was not chirping this time. In fact, his voice sounded almost pensive. "I do find a lot of things fascinating. I find it fascinating that you seem completely unaware of the Arthurian legends, but somehow know the name of a famous instrument created in the 32nd century. I find it interesting that you believe I've been solving complex equations on the prison walls when everyone else I've asked has told me in no uncertain terms that they are meaningless squiggles. But you know what I find most fascinating? I find it utterly baffling that the moment I was arrested, I was immediately asked for my sonic screwdriver, despite the fact that I have it on good authority from the folks at the crime lab that there is no such thing and only a madman would dream of such an item." On this last sentence, his voice turned low and angry. "So if you could please drop this charade and tell me who you are, I would very much appreciate it. After all, you clearly know far too much about me."

"My name is Dr Bradshaw," said Dr Bradshaw.

"Oh, really?" said the Brit. "Just an American Midwesterner who doesn't know about baseball and apple pie? Who has no idea about the Boston Tea Party or George Washington crossing the Delaware? A simple man who believes that the current president is Bruce Wayne and that elections only occur once every twenty years? I've talked to a lot of humans, and I've talked to a lot of Americans, and you are certainly neither. So stop all this nonsense and tell me who you are."

Dr Bradshaw didn't say anything for a moment. But when he began speaking again, he didn't sound rattled or shaken by the previous demand. "Mr. Smith," he said, "since you clearly believe what you say, I can only assume you have some severe mental instability, which I'm sure I can help you to work through in the future. But unfortunately, it appears that we've run out of time for this session."

Suddenly, the sound of five guns cocking at the same time rung out from the tape. Sara stared at Grissom, as a rather hesitant British voice said, "Oh. So I guess this means I'm not leaving yet."

"No, Doctor," said Dr Bradshaw. "Certainly not."

The recording ended.

Sara just kept staring at Grissom, not quite sure what to say. After a long moment, she finally found her voice. "What… what happened?"

Grissom turned over the tape, and pressed the play button again.

Dr Bradshaw's voice came over the speaker, once more giving the date and time, and an account of his patient, which appeared to be interrupted by bitter laughter. Dr Bradshaw ignored the laughter, instead continuing with his questions.

"Dr Smith," he said, "yesterday you told me that you believed that we were trying to hurt you."

"Oh yes," came the British voice, but he did not sound upbeat or chirpy. The voice was tired, worn out, scratchy along the edges. It came with a sort of cold, resigned bitterness. "I have to admit, though, I was expecting you to try to disprove it. It appears you took the other approach."

"Do you feel trapped, Doctor?" asked Dr Bradshaw, almost smugly.

"That's your way of gloating at me, is it?" the British voice asked. "That's your way of telling me that you've succeeded where hundreds of others have failed? The poor, helpless Doctor, tied to a bed, being treated to a rather unpleasant bout of electroshock therapy." He gave a few labored breaths, and then said, in a gentler voice, "I can help you, Bradshaw."

"Do you think I need help, Doctor?"

"I know you need help," the British man replied. "I can feel it in the air. It's that bitter taste of time being all tangled up and frayed at the edges. You're bleeding it, spreading it like an infection. I'm the only one who can help you. Just tell me what's wrong."

Sara was the one who turned off the tape. She couldn't stand it anymore. "I…" she said.

"It wasn't you," said Grissom, but she wasn't listening.

"I put him there," said Sara. "That was my case. I thought he was guilty. And maybe he was, and maybe he wasn't. But I didn't want that to happen."

"This wasn't your fault, Sara," said Grissom. "Smith didn't blame you. I don't blame you. You have to stop blaming yourself."

Sara considered this for a moment. She recalled that cheerful British voice on the recording she found in Verity's office, talking about the guilt eating away at everything inside. He was right. She had to let it go. She swallowed, and asked, "Are all the tapes like that?"

Grissom fast forwarded the tape to the end, ejected it, and filed it away with the others. "Variations on a theme," said Grissom. "Every time, Dr Bradshaw asks him the same question: 'Do you feel trapped?' And every time, the vic sounds worse and worse."

Sara thought about all the people on that list. All the people this man had apparently murdered. And she asked the only question she could think of. "Does he deserve it?"

Grissom contemplated the question for a long time. "Dr Bradshaw asked him that too," he said. "That's another one of those questions that keeps coming up. And Smith always gives the same answer." He looks at Sara, sorrow in his eyes. "He says yes, but not from you."