The Doctor was still turning over the remains of Watterson's machine when Mulder returned to the laboratory. "The video monitors didn't pick up anything," he said.
"What, nothing?" That seemed to surprise the Doctor as well.
"The monitors were off in here. If Watterson was experimenting by himself he wanted it kept secret." Mulder scanned the desk in the control room, just for something to do.
"Whoever killed him still had to pass through the rest of the building."
"You don't seem to have."
"Touche," said the Doctor cheerfully. He either didn't realize that this made him a suspect (and, so far, the only one), or didn't care.
"In any case, the killer didn't set off the security systems. It's a new experimental system, brainchild of one of the other researchers here. Didn't seem to be working last night."
"Experimental?"
"Temperature-sensitive. It's dormant until it senses body heat."
"Ah!" That seemed to answer a question for the Doctor.
"What is it?"
"Not every living thing has a human's body temperature, Agent Mulder."
"You think an animal killed him?"
The Doctor only smiled. Then Scully returned. There was nothing helpful in what she'd learned at the police station; except that while she was there a homeless man had been brought in, found behind the Greyhound station six blocks away, killed in an identical manner to Dr. Watterson - a single, powerful blow to the back of the neck. But the homeless man's brain had been removed.
"His brain?" Mulder asked. "What would the killer want with his brain?"
"The killer must have wanted it pretty badly," said Scully. "It was removed with surgical precision."
"His brain ..." The Doctor thought for a moment. "What use would a human brain be to a ..." He wandered back across the room, lost in thought.
Scully turned to Mulder. "May I see you, out in the hall?"
"Sure."
When they were alone Scully brought out several fax pages. "I requested information from UNIT through channels and got this just as I left the police station. This Doctor seems to have been British UNIT's unpaid scientific advisor in the seventies, under a Brigadier Lethbridge-Stewart. His name is John Smith." Scully paged through the fax. "... No, that's only a pseudonym. His real name isn't in the file."
"'Unpaid scientific advisor'," repeated Mulder.
"His exact duties and actions all seem to be classified. Most of the file is blacked out. Mulder ..." Scully was confounded by what few hard facts there were about this person. "The file speaks of a single man known as 'the Doctor' to British UNIT, but there are photographs of several different men here - including our friend - who are identified as this Doctor. Any one of them are to be treated as if they were him."
"Do you suppose I'm the Bureau's paid unscientific advisor?" Mulder in turn briefed Scully about the singular occurrence of what the security system did in the night-time.
"Just like the Doctor this morning," Scully noticed too. "That makes him a suspect."
Mulder had had longer to think about it, and shook his head. "I think, if he was the killer, he'd have to be pretty stupid to demonstrate his burglary skills at the scene of the crime the very next morning. He doesn't come off as very attached to your reality and mine - but he's with UNIT, and he identified the Watterson device. I don't think he's stupid."
"What do you think of him?"
Well, she asked. "I think he's a time traveler," said Mulder.
"Mulder," said Scully in that tone.
"Think about it. It was a time experiment gone wrong that started all this. Then this guy shows up, wearing clothes about as fashionable as Bozo's. Maybe his home time's so far off, they think that's what we wear in the twentieth century."
"Time travel isn't possible."
"Not according to your own thesis on Einstein. I've read it. You said the laws of physics don't rule out time travel, but it'd 'exceed the limits of human endurance'. You completely overlooked the possibilty of time-traveling inside a protective suit, or a vehicle. Or a 'relative dimensional field', whatever that is."
"So what is he here for?" Scully asked. Or is it, "now for"? Mulder wondered. "Do you think he's supplying the project with time travel secrets?"
"No," said Mulder. "He didn't show up until the accident. I think he's here to shut it down."
"Time travel." Scully stared at Mulder for several moments, then said, "Mulder, this is my last X-File."
"What?"
"I'm going to request a transfer when we get back to Washington."
"Why?"
"I've had it, Mulder. Sometimes I think you have no objectivity at all. I suppose you think your 'anachronism' in the lobby is the Doctor's protective vehicle. Mulder, I ... I've just had it. I'm sorry."
Mulder looked her in the eyes, and saw that she meant it. He was trying to formulate a reply - perhaps "Why are you sorry?" - when inside the lab the Doctor let out a loud cry and charged into the hall, unconcernedly breaking the yellow police line tape. "Is something wrong?" Mulder asked.
"If I'm right," said the Doctor, "we must find the being who killed Dr. Watterson, or all of human history is doomed."
--
The smoking man sat in one of his offices. Open on his desk lay a copy of the file that had so bemused Scully; but a considerably lower-generation copy, and with none of the security blacking. When the phone rang he picked up the receiver.
"Your transatlantic call, sir," said a female voice. There were two foreign-sounding rings, and a male, cultured British voice answered, "Lethbridge-Stewart."
"Alistair," said the smoking man. "Good to hear your voice."
There was a long pause; then, "It's you."
"How's retirement?"
"It might be the greatest service I ever did to mankind if I could persuade you to find out for yourself."
The smoking man elected not to take offense, though he was aware of the illustriousness of the list of achievements to which the other was comparing this proposed service. "I have some questions about your friend the Doctor."
Suddenly the voice on the other end was amused. "Oh, he's crossed your path, has he? And you have questions. Well, I'd wish you luck of the answers, were I inclined to wish you luck of anything."
"I wondered if you would expand on what's in your UNIT files on him? For old times' sake."
"Only that you're the second-best personification I know, of everything he fights against and wins. Good day." The line went dead.
The smoking man replaced the receiver in the cradle. He had almost, but not quite, learned little enough to regret having made the call.
--
Before the agents could ask the Doctor what he meant, he had turned toward the elevator and punched the down button. The elevator doors opened almost immediately and he stepped in. "Coming?" he snapped to them.
In the lobby he led them to the police box, unlocked it, told them, "Wait here," and disappeared into it. Scully avoided looking at Mulder during the few moments the Doctor was inside. When he came out, instead of his umbrella he was holding a small boxy device in his hand, at which Scully didn't get a clear look before the Doctor barrelled out of the building ahead of them. Just outside the doors he came to a complete halt. "Which way is the bus station?"
"That way, up Seventh," said Scully. When Mulder looked at her, either startled or amused that she knew, she explained, "It's on the way to the police station."
"We have a car," Mulder volunteered, just as the Doctor said, "You have a car, don't you?" "This way," said Mulder.
Mulder ran to the driver's door and the Doctor jumped into the front on the other side. Scully wondered, as she climbed in behind the Doctor and Mulder belatedly asked her for the keys back, why she was coming along and whether they would have noticed if she hadn't. Mulder pulled out onto Seventh into moderate midday traffic.
Now she got a better look at the thing in the Doctor's hand. It looked like a STAR TREK prop. From the '60s, too, not even a modern STAR TREK prop. There was a dial and two buttons, and a light that flashed in time with an infrequent beeping noise. The Doctor was pointing it north up Seventh, which was fortunate, as Seventh was one way, north. "Tracking device?" Scully guessed sarcastically.
The Doctor looked at her with a delighted, disarming grin of which the earlier one at their first meeting was a mere shadow. "Yes! I can tell you're the brains." Scully decided he was serious, and debated whether to disabuse him of the impression that she had been.
"Then explain to me," said Mulder, "how your tracking device can pick out our suspect from everyone else in downtown Louisville." Mulder's use of the word "suspect" reminded Scully suddenly that the only real suspect they had was the man leading them on this wild goose chase. Or red herring chase, as the case may be.
"For the same reason your fancy temperature-sensitive security system couldn't track her," said the Doctor. "Our quarry is cold-blooded."
"Cold blooded?" said Scully. "We're after an animal?"
The Doctor didn't answer. The beep rate had increased as they passed the White Castle at Broadway. "It looks like she's still in the area," mumbled the Doctor.
"'She'?" said Scully.
"You know who it is?" Mulder asked.
The Doctor didn't respond to them. Scully thought she might like playing straight man better if she ever got to hear the punchlines. Maybe the Doctor wasn't the killer; if he were, it certainly wouldn't be in his best interests to cultivate the investigators' company only to annoy them like this. That would take a fantastic ego ... which hypothesis, come to think of it, wasn't inconsistent with the Doctor's behavior as observed so far.
They crossed Chestnut Street. The beeping was now nearly a steady stream of noise. As they approached the bus station the Doctor turned the tracker sharply left, to the west. "Stop! Stop!" Mulder pulled to a stop and the Doctor popped out of the car in the middle of traffic, running into the parking lot of the building south of the bus depot. Someone in a car behind honked, and Mulder started moving again before Scully could follow the Doctor out of the car. He had spotted an open parking place just ahead, on the left side of the street; Mulder pulled in and both agents jumped out to chase the Doctor.
The north side of the building was a loading dock area, with several vehicles parked at the dock, and at the brick wall that marked the north property line; but empty of people for the lunch hour, except for the Doctor. Approaching from the east they found him standing in the middle of the loading dock area, his attention riveted to his tracker. But before they could close on him enough to speak, he looked up and began shouting. "Come on out! I know you're here, I want to help you!"
He deigned to notice Mulder and Scully only long enough to wave them off. "I can take you home!" the Doctor continued. "I know why you need to go! I need you to go!"
"What's this about going home?" Scully demanded. The Doctor hushed her with a gesture, and Mulder raised a finger to his lips too. Fine, she thought, and crossed her arms. She and Mulder kept a slow pace, passing the Doctor, moving toward the west driveway into the loading dock area.
"I know who you are!" the Doctor called. "You're Zhessil, aren't you? You must go home! History demands you go home!"
That seemed to be the end of the Doctor's prepared argument with the unseen other. He fell silent, and stood looking around expectantly. Mulder was visually scanning the loading dock area too. Scully remained alert but wasn't expecting anything to happen.
Two men in commando outfits carrying nonstandard rifles came around the west corner of the building, and started running toward the Doctor and the agents. One halted immediately they came into view, raised his rifle and fired. Mulder and Scully were whipping out their pistols now. Scully shot at the commando who'd fired as she heard Mulder squeeze off a shot too. The first commando had started running now again, but went down. The other had pulled to a stop and now got off a shot, but someone, something, had jumped out in front of him - from behind a van at the brick wall bordering the loading dock area to the north - took his fire point blank, and now dropped to the ground. The first commando got off another shot and started to his feet as Mulder and Scully started charging them. People were poking their heads out of the building or around the corner from the parking lot, many of them college-age (Scully learned later that the building was a vocational college). The second commando, unwilling to pursue his goal against the combined force of the agents or in front of an audience, started backing off, covering Mulder and Scully, and by the time he was back to where the first commando had fallen the first commando was standing. They both turned and ran, the first one with an arm dangling limply.
Scully ran to the fallen - creature. Mulder made as if to follow the commandos, but Scully looked behind them to confirm something. "Forget them, Mulder, the Doctor's down."
Mulder turned back as Scully bent to examine the second commando's victim. It - the Doctor had seemed to think it would be female - was human in shape and unclothed, but the epidermis was dry and scaly like a reptile. She felt for a pulse and found none. She turned it over on its back and checked for respiration - noting its slitted pupils, its hard ridgy mouth - and found none. There was a large wound in the middle of its chest. In the middle of the wound was a tranquilizer dart - Scully wasn't surprised; she had recognized the rifle type from nature programs she'd watched. But these weren't meant to be fired at such short range.
The reptile person was dead.
--
The Doctor was struggling to remain conscious as Mulder ran up. "Must get her into my TARDIS," he said, waving toward the second commando's victim with the hand that held the dart he'd pulled out of himself. "Can't stay here." He collapsed into unconsciousness.
Mulder felt for his pulse. He tried to make sense of it for several moments and gave up. He looked up at Scully just as she looked over at him and shook her head over the other shooting victim. Mulder made a decision. "Get her into the car," he called.
"Leave a murder scene, Mulder?" Scully shouted back. "With the body?"
"Doctor's orders," Mulder said, stooping to pick up the Doctor. To Mulder's surprise, that seemed to convince her. Mulder carried the Doctor and Scully carried the other back to the rental car in fireman carries, flashing their badges at the onlookers as they went to give a veneer of authority to their illegal action.
"Tranquilizer darts," Mulder said as they sat the Doctor and the creature in the back seat. "Whoever they were, they wanted to take her alive."
"Mulder, they weren't after her," said Scully. "She was still in hiding when they moved in."
"Then ..."
"They were after the Doctor."