The Doctor was working to rebuild the TARDIS after the Master had made it into a paradox machine, and Jack and Martha were helping him. The conversation had first been about the TARDIS and time travel, and then took a side route towards visiting alien planets, and then ended up on a jaunt about just how many worlds the Doctor had saved.

"I stopped counting a while ago," the Doctor insisted, and then searched around in the toolbox for the Hypo-clamp. He had a bruised shin, two swollen fingers, and dropped a wrench on his foot. He now remembered why this version of him merely whacked the console with a hammer instead of tinkering like his previous self.

"Seriously," Martha said, handing him the hypo-clamp. "It's kind of ridiculous."

Jack said, "If you've lost count…does that mean all of them?"

"Of course not, don't be silly," the Doctor said, connecting the stabilizers back into the control circuit. "If I had, there'd be no where else for me to go." And that would be unfortunate, since he loved traveling to unknown places.

"'Boldly going where no man has gone before'?" Jack asked.

"Sort of," the Doctor said, getting the reference. "Well, what do you mean by 'man'? What do you mean by 'boldly'? I just sort of sight-see."

"And save the world," Martha pointed out. Well, he couldn't argue with that, not after a year like the one that just disappeared. He nodded.

"I was wondering, Doctor," Jack said, recalibrating the transit loop and syncing it with the console. "All those worlds. Isn't there sometimes some who can't be saved?"

"How d'you mean?" the Doctor mumbled, his sonic in his mouth as he peered through his specs at the TARDIS innards. He wasn't sure whether or not he liked where this was going.

"Like what if some war or alien comes to a planet, and it's supposed to happen like that, but then you rush in and save the day. That's like violating the Prime Directive!"

"No, it's not," The Doctor said defensively, relieved Jack wasn't talking about what he thought he was talking about. "I try to stay away from fixed points."

"And those are?" Martha asked.

"A fixed point is a spot in time and space where an event must happen, no 'if's, 'and's, or 'but's," the Doctor explained.

"How do you know what they are?" she wondered.

"Time Lord," The Doctor said, grinning. She rolled her eyes. "Anyway, the aliens or invaders or whatever are the ones violating the Prime Directive," the Doctor said. "I'm the one who puts it right. Mostly," he amended.

Martha pulled a face at him, not understanding. "What are you two going on about?" she demanded.

The Doctor blinked, recalling memories from his previous self. Give me some Spock! Just once, would it kill you? The blond in the union jack had asked.

"Star Trek," Jack explained. "I didn't know you were a fan, Doctor."

"I'm not," The Doctor mumbled, shoving his head into the conduit to fix the wiring. He frowned at the memories.

"The Prime Directive is sort of a non-interference code," Jack explained to Martha. "The crew of the USS Enterprise isn't allowed to mess with the growth of planets that…oh… aren't up to their level of development."

"Not allowed to give a cave man fire before he finds it, right?" Martha guessed.

"Yep," Jack agreed. "So, Doctor. Favorite character?"

He mumbled something from inside the wall.

"What's that?" Martha asked.

Louder mumbling, but still unintelligible.

"What d'ya want to bet he's got the sonic in his mouth?" Martha asked, getting up from the floor. "I'm off, boys. Play nice."

"Where are you going?" Jack asked.

"Dinner with my family," Martha said. "Novel concept." The creak of the TARDIS hinges signaled her departure.

The Doctor immerged from the wall with even crazier hair than usual and the sonic screwdriver wedged securely between his teeth.

"Weren't you going to go check on your team?" he asked jack.

"Sure. Right after you tell me your favorite character."

"I already did!" The Doctor said, exasperated.

"Yeah, right. If you don't tell me, I'm going to guess." Jack folded his arms.

The Doctor rolled his eyes. "Spock!" he snapped.

"That was one of my two choices," Jack said smugly. "The whole I'm-an-alien-and-no-one-understands-me vibe, or the Captain Kirk I'm-married-to-my-ship-and-everyone-tries-to-steal-it-from-me sort of thing."

"Aren't you going?" The Doctor said.

"Yeah," Jack said, taking the hint and grabbing his coat from where it hung on the railing. "Night, Doc."

"Don't call me Doc," the Doctor said as Jack left. That could just lead to far too many Bugs Bunny and Elmer Fudd jokes. As the TARDIS doors creaked shut, the Doctor finished piecing back together the brakes and time rotor, and decided to call it a day. He wanted a banana and a strong cup of tea.

As he ambled into the kitchen (intact, mostly; the Master hadn't much cared for anything besides the console room), he wondered what he did with those Star Trek DVD's. They were probably buried somewhere in the media room. He didn't particularly care for the science in the show (it was totally off base) but he could hear a voice in his head, saying, "Oh come off it, Doctor, sit down and watch!" as an arm clad in pink pulled him down onto the sofa. "It's all about the characters, anyway."

He carried his banana and tea through the TARDIS hallways to the media room, digging through the stacks of movies before he realized he was in the future episodes of Fringe and the new Star Trek movies. "Oops," he mumbled to himself, moving to the past section. Ah, there we go. Star Trek the Original Series –lots of large computers and odd costumes and funny makeup. He slipped the DVD into the TARDIS bank and waited for the screen to come on.

As the cheerful episode "Trouble with Tribbles" began to roll, the Doctor thought that maybe, if he thought about it, he could recall the last time he watched this, with a girl just to his right, curled up on the sofa, laughing at Spock and McCoy and cooing over the Tribbles. She had made him like the series, get into the characters, and he ended up liking Spock (even though he refused to act like him) because she did. He thought maybe, if he tried hard enough, he could still feel her head on his shoulder where she fell asleep during a Star Trek marathon she had insisted they have, hear her breathing.

He sighed. Rose, I miss you.