The Doctor and related characters belong to the BBC. Durr.
The Doctor danced.
Around the TARDIS console, with the almost-practised pilot flow of lives, of the last, he danced. Bring the switches up here, the knobs over there, press the vorestat buttons, mind the thrivics...
slam your hand there-
-the room twisted-
The Doctor clung to the console as the room bucked, seven dimensions spinning and peeling apart before all his Time Lord senses. There was a racket of hums from the console. A rising cascade of alarms began to follow.
"Blast it, stop! I can't concentrate-"
The Doctor staggered, his hand grabbing at the mallet from under the console just as his feet swept out from under him and he flew across the room. He braced himself against a trip into the iron grating...
He slammed into a white wall.
He sliiid down.
"Oww. That was a little harsh, girl. Didn't mean it that-"
"Who in the name of seven blazing suns are you?!"
The Doctor stood back up, his head still ringing."You mind repeating that? And what the hell are you doing on my TARDIS?"
"Your TARDIS? You thuggish buffoon, I still have not worked out how you could possibly have transmatted onto my ship, but I have more pressing concerns here!" The other fellow darted over to another end of the main console. With great facility, but little effect, he was pressing knobs, pulling buttons, and wrenching dials.
"Oh, no," said the Doctor. "Oh no, no, no..."
The other fellow ran over to the main screen. He flipped two switches, then looked at the display, his face a study in annoyance. "What in thunderation!" He rounded on the Doctor. "You blithering fool! You just had to display such incompetence in your TARDIS piloting to collide with me, right when I was repairing my shields!" A loud WHOOPing began to fill the room.
"A level five alert!" He paused, a look of puzzlement crossing his face, before shrugging and charging back over to the console.
The Doctor strolled over to the console. "What were you thinking, doing your major repairs in mid-flight, Doctor?"
He was beginning to have a glimmering of memory... This could be trouble.
"Look, let's get this out of the way," he said. "I'm-"
"I am perfectly aware of who you are," said the other Doctor sharply. "Two TARDISes colliding, yet reading as one? A fumble-fingered paradox if I've ever seen one."
"Well! Glad to hear it!" said the Doctor with a grin. "On to the matter at-"
"What I don't understand," said the other, rounding on him from the console,"is why you thought this would work any better than what you already tried at the trial!"
The Doctor's grin dropped.
"Wait, wait, wait," he said, backing away as the curly-haired Doctor advanced on him. "You- you think I'm-"
"Enough of your games, Valeyard!" shouted the other Doctor, launching himself at him and bearing him to the ground. "I don't know whose body you managed to steal this time, but I will make you pay!"
As the Doctors struggled, another siren began to sound. "Level- Ten!" gasped the older Doctor. "We've got to deal with this- before we tear a hole in space-time!"
"I'm willing to take the chance," snarled the other,"if it means you're gone, too."
The Doctor's face hardened, and he stared into his younger self's eyes. "You're serious."
The Doctor suddenly flipped the other up against a wall, pinning him there with a jacketed forearm across his throat. He glared into his face. "You damned idiot! Stop flailing about like a damaged child, and remember just who you are!" He slammed his back into the wall again for emphasis, before fully regaining his feet. He picked up the mallet from where it had dropped, and stalked back toward the console.
"Stop! What- doing-" the younger Doctor clutched at his throat, coughing and gasping.
Both Doctors looked up,
"The Cloister bell!" they said unison.
The younger Doctor managed to regain his feet and staggered toward the console, glaring at the Doctor. "I suppose you think you've won," he croaked, as he began frantically working the controls.
The Doctor sighed, then grabbed his younger self's shoulder, yanking him away.
"Watch carefully," he said, " 'cause next time, it's you who's gonna have to do this."
His hands flew across the controls.
"Sideral thrust to level twenty-seven, tachyon dusters to three-quarters... and just for the final touch..."
He glanced over at the younger Doctor, who was staring at him and the controls with a look of dawning horrified realization, grinned, and flourished the mallet.
"I'm afraid this is another bit you're going to have to fix," he said, and brought the mallet down on a knob, driving it into the console.
There was a WHUMP that was felt throughout the TARDIS, and a rippling wave of force washed out from the console's center. Both Doctors were flung back...
As the Doctor rocketed back toward the wall, the room shimmered before his vision, wavering and then solidifying into his own familiar TARDIS, the green of the console's centerpiece pulsing at a steady rate.
He grinned in relief. "Fanta-"
-he slammed once again into the wall and fell to the grating.
"Well, that was different," grumbled the Doctor as he got back to his feet. "Though I guess I know now why the Rani had such an easy time taking me out... never did get back around to fixing the shields proper."
As he made his way back over to the console to check for damage, he heard the sound of running feet. He turned, and beheld Jack racing into the console room, somehow having armed himself.
"What the hell was that?!" said Jack, looking wildly about.
"For Gods sakes, put that thing away!" said the Doctor crossly. "Forgot I had that thing around, anyway. Don't trigger it in here- takes ages to get the green foam out of everything." He turned back to the console.
Jack blinked, then carefully laid the gun aside. He walked over to where the Doctor was working at some controls, scanning over them with his sonic screwdriver.
"What was that..." Jack shook his head. "Geez," he said with a chuckle, "I can't even describe it."
The Doctor didn't turn around. "Just a pothole."
"A pothole." Jack stared at The Doctor's back for a second.
"That's right, Jack." The Doctor turned around and gazed into his face levelly. "Thought you'd been a Time Agent. Don't you recognize a temporal pothole when you hit one?"
Without waiting for an answer, the Doctor ambled over to the other side of the console to check some other controls.
Jack stood there a moment, then sighed.
"Yeah, Doctor, I guess I do," he said.
As he walked back toward the door deeper into the TARDIS, he sighed, then laughed to himself.
"The hole in my memory... just a damn two-year temporal pothole."
This takes place for the Sixth Doctor sometime after Trial of a Time Lord, and for the Ninth, shortly after The Doctor Dances.