DISCLAIMER: I own nothing about Doctor Who. Characters, settings, whatever. Most of the characters presented in this fic will be OCs but probably a lot of aliens from the show. A quick note on the time scale: this is set sometime into the Eleventh Doctor's tenure, so after the present (as of early 2010) series.

*

Space.

Massive.

Stars shone; nebulae swirled; planets orbited their respective suns.

The TARDIS plunged through a supernova, the Eleventh Doctor desperately clinging on to its door, shields nearly failing as the burning star surrounded it.

The blue box shot through the supernova; the Doctor pulled himself inside and slammed the door, leaping for the fiery controls. Yanking his hand back as the sound of frying flesh sizzled from the panel, the Time Lord made a dash for the fire extinguisher, unbuttoned tweed jacket flapping as he ran through the gargantuan interior of the tiny box.

'Come on!' he yelled at his breaking machine, punching buttons as he blasted the fire extinguisher one-handedly at anything burning.

Which was pretty much the entire TARDIS.

The loud thrumming from the terminal suddenly intensified, like an overheating computer.

'No!' the Doctor cried, dropping the extinguisher as both hands ran through his hair in frustration. 'Not already!'

A loud crash signalled the falling of a large pillar; the Doctor dived to the floor, grunting as he landed awkwardly on the metal grating. The thrumming grew still louder, the mechanism in the pillar pumping faster than it had ever worked before, the flames spreading as the TARDIS broke and collapsed around the Doctor, and then - silence.

A red glow filled the inside of the TARDIS, the terminal exuding a weird dark light. The Doctor stood slowly, hand again pulling at his hair.

'I haven't been me long enough,' he said, pleadingly.

The light seemed to harden, defiant and authoritative.

'Don't do this. Please.'

The walls of the TARDIS collapsed, space falling in. The Doctor stood immobile, staring at something unmoving amongst the chaos of a dying dimension.

Reality vanished, sucked away quicker than a dematerialising TARDIS. Still, the Doctor didn't move.

And another TARDIS fell into the first.

The Doctor's eyes moved. 'What?'

The doors opened, and the Tenth Doctor looked out, tears in his eyes. 'I don't want to go,' he said, almost desperately.

The Eleventh Doctor suddenly moved, jumping into the Tenth's TARDIS, his jacket falling loose and dropping to the floor.

'Doctor!'

The Tenth Doctor raised his head, spreading his arms wide; golden energy streamed from his hands and face.

'No!' the Eleventh shouted, sprinting towards himself.

The red glow filled the Tenth Doctor's TARDIS, and with a last scream, the regeneration ceased. The Doctor fell backwards, arms still spread-eagled, eyes open and glazed.

The Eleventh Doctor fell on top of his past self, sobbing, cradling him gently. He knew what was happening, of course; he was the Doctor. But the knowledge of what was about to come would not make it easier.

It was a paradox. The TARDIS, burning and dying after the Sontarans had sabotaged it, causing the Doctor to crash it into a neutron star, had used its only possible source of energy to stay alive: itself. It had cannibalised itself and become a Paradox Machine, but even that wasn't enough to keep itself going. All it could do was create rents in time, stealing the energy like a hungry Reaper. So it had found the biggest paradox it could. Another Paradox Machine. One created by another version of itself, containing another version of its passenger.

The Doctor let out a scream muffled by incessant sobs, clutching his past self tightly. The Paradox Machine was making him impossible, taking his life force to keep itself alive. He could feel it forcing him and himself together, trying to make him as much of an impossibility as it could.

Golden energy radiated from his hands, gently lighting his dead past self's face.

'Too soon,' the Doctor whispered through a sob. 'Too soon.'

Regeneration might have been saving himself from death, but it never got easier.

Every time, it felt more like dying.

It was dying.

The Doctor stood, feeling the paradox push his two selves together. He dropped his arms, the energy pouring from his hands, as the Tenth Doctor's body merged with his.

The paradox complete, but not enough to sustain it, the Paradox Machine faded away. The Tenth Doctor's TARDIS slowly morphed back into its original, beautiful self.

The Eleventh Doctor sighed, taking it all in through the haze of golden light swimming in front of his face. He raised his hands again, closing his eyes with a deep breath.

'Don't make this too hard,' he breathed.

And died.

*

The energy cascaded from the Doctor's skin as he screamed, his face upturned. Everything the Eleventh had ever known rushed through his mind, the knowledge of ten past lives streaming underneath.

And everything the Eleventh had been was stripped away, and everything that the Twelfth was poured in.

The flow of energy ceased.

The Twelfth Doctor breathed.

He stood, arms still outstretched, with his eyes closed, remembering what he had lost.

Mourning himself.

And then he turned to the terminal of the TARDIS, and pressed a few buttons.

And then post-regenerative hyperactivity kicked in.

Laughing, shouting wordless shouts, filled with excess regenerative energy, the Doctor danced around the TARDIS, testing his mobility. Shaking each limb in turn to ensure its presence in the correct place, he leapt nimbly onto the TARDIS console, jabbing at buttons, tugging on levers, yelling names of obscure planets: 'Felspoon! Polongus! Balhoon!'

Twisting a knob he didn't think he'd ever even noticed before, he settled on one. His favourite planet: 'EARTH!'

*

Thanks for reading! Please review, comments and constructive criticism appreciated.

-

Next time: What has the Doctor's new regeneration become? And who will his latest companion be? The answers are revealed on Earth, in chapter 2!