Regeneration!

A hole had been blown open in the tower roof. Snow drifted through the gap onto the **** girl lying on the floor, as a breeze tickled her bare skin and disturbed her brown hair.

Clara groggily opened her eyes, briefly confused about where she was and why she was covered in a dusting of snow.

"Doctor!"

The brunette sat up, whincing as pain shot through her sore body...and hugged her knees to her chest when the sight of her bare legs and feet reminded her that she was naked.

Glancing around, Clara saw a blanket draped over a chair. She scrambled across the room and wrapped it around herself. The brunette tried to rub warmth into her still bare shoulders and arms as she exited the tower.

Her bare feet still hadn't got used to the snow-covered ground, and the warmth provided by her blanket was little better than her birthday suit.

The TARDIS door stood ajar, but more alarmingly, the external emergency telephone was hanging off its hook.

Keeping one hand on her blanket, Clara replaced the phone and stepped inside the time machine.

The Doctor's battered old coat that he'd been wearing in the village was discarded on the floor; the brunette wasted no time in scooping it up and draping it around her shoulders.

She turned on her bare feet upon hearing footsteps coming down the stairs.

"Doctor! You're young again."

Clara started towards him, but the timelord held out a hand, keeping her at a distance.

"It's started—a whole new regeneration cycle. Just taking a bit longer to break it in, that's all."

Clara jumped in fright as a vision of a red-haired woman walked down the stairs and embraced the Doctor.

"Amelia."

"Who's Amelia?" Clara asked, not noticing that her blanket had fallen to the floor.

"The first face this face saw. We all change. We're all different people through our lives, and that's OK, as long as you remember the people that you used to be. I will not forget one line of this. Not one day. I swear. I will always remember when the Doctor was me."

The Doctor removes his bowtie as his hand starts to glow, a pained expression on his face.

He jerks backwards, and then forwards, taking on the appearance of a tall, grey-haired man with piercing blue eyes.

Clara backs away, but he's too fast for her and clutches the sleeve of her coat. A few seconds of grappling, and the coat is pulled clean off her shoulders.

"Kidneys! I've got new kidneys!" The man announced, studying the coat for a few moments before tossing it aside. "I don't like the colour."

"Of your kidneys?" came the squeak from the girl crouched behind the console. She staggered from her hiding place as the TARDIS shuddered.

The Doctor grabbed her before she fell, keeping a vice-like grip on her forearms; Clara squirmed at the realisation that she was once again exposed.

"Stay calm. Just one question. Do you happen to know how to fly this thing?"