The Doctor does some maintenance on the Tardis, with unexpected side effects for Rose.
"What?!" she yelled from down the corridor.
"Where's my sonic screwdriver?"
"It's in your pocket!"
"I'm not wearing my pocket!"
"Huh?" Rose stuck her head into the Tardis console room and looked around. The Doctor was indeed not wearing his pockets. He was in his shirtsleeves, buried upside down halfway in the Tardis decking as he did something unexplainable to the Tardis. His hand waved vaguely in the direction of his coat and jacket which were thrown over the curved support nearest the door.
Rose rolled her eyes and went to get it for him. "Here." She slapped his screwdriver into his groping hand and crouched down trying to see what he was doing.
"Wonderful. Thank you." He twirled the screwdriver in his hand, took a firm grip, and whacked the butt of it against some recalcitrant piece of machinery above him. Something popped loose with a faint gonging sound. "Hold this for a minute." With a few wiggling gyrations, he managed to make enough room to get the piece free of the deckplates, and handed her what looked like a huge pop bottle cap, a foot and a half in diameter.
She turned it over, staring at it, it even had a wavy line etched in the metal, like the Coca Cola logo. The Doctor grunted and wiggled, managing to fold more of his skinny self into the tight space, he got his feet under him and pushed upward, toward the deckplates, but he didn't emerge above them. Rose's eyes widened and she knelt down, staring into the repair well. The Doctor's feet were still there, but the upper half of his body had disappeared. He raised one leg as if he was bracing his knee on a ledge to hike himself higher, his other foot came up off the plating and Rose panicked.
"What are you doing?!"
The foot settled back down again, and the Doctor's voice answered, echoing as if from a large barren space. "I thought it was about time I fixed the gravitic stabalizers."
"But, where are you going?" She looked above the decking then below. That was impossible. She was tempted to grab his ankle before he disappeared entirely.
He sighed. "I need to realign the relative kinetic buffers. And from the sound of things I'm going to have to pull the lateral balance cones, again. I..."
"Oh, shut up," Rose whispered to herself. He could go on like this for days. "Budge up." she yelled and lowered herself down into the repair well. His legs moved a half step backward and she twisted around, and looked up. The Doctor's body ended at his hips. The upper half of his body disappeared into a blackness the same diameter as the bottlecap he'd given her. She was no better informed than before she'd seen it.
"Well, if you're just going to sit there, give us a leg up." One white sneakered foot raised, blue suited leg bent, waiting. Reluctantly, she braced her elbow on the flooring and he stepped into her palm and boosted the rest of himself up into the blackness, twisting as if he was sitting on a ledge, then pulling his legs up. The second his soles disappeared, the blackness vanished. Leaving Rose looking up through the deckplates at the console.
The stead hum of the Tardis abruptly died. The green glow of the console faded to black. The spotlights all around the console room popped, one after another, like a string of firecrackers. Rose jumped and twisted. That impossible ambient light that always filled the Tardis faded away, there was no sound. No clicks, no whirs, no sighing life. Dead, dark, and silent. Alone. Adrift in space. No Doctor.
Then the gravity failed.