It's all AU.

Scowling at his TARDIS, Theta reached for the mallet hanging from the control panel, intent on giving the recalcitrant machine a good whap. Only to have it shut off completely before he could do so, even the lights fading to almost nothing, and the door opening.

"What? Dismissing me? Oi!" He glared at the central column, crossing his arms over his chest. "Take me back home!"

"Come on, then! A whole new world, just beyond these doors." The Doctor grinned over his shoulder at Jack and Tosh, throwing open the door to the TARDIS. Turning back, he stepped out, his grin fading a little when he didn't see the dark purple trees he'd been expecting. Or the blue ferny ground cover.

Spinning around, he yelped when he didn't see his TARDIS. "What? But... Oh, bloody hello!" He glared at the empty air, and the gleaming lake. At least he'd already shown Tosh the quick return switch. Except... the TARDIS didn't rematerialize. Several minutes passed, and he was still staring at an empty expanse of green grass, and a lot of water.

"Tosh'll figure out how to pilot it. Between her and Jack, they'll figure it out," he muttered to himself, turning away from the lake. A computer genius and a pilot - they'd better figure it out, because he really didn't want to be stuck anywhere again.

Sighing, he rubbed the back of his neck, grimacing as he set out on the dirt path that meandered through the trees, shoving his hands into his pockets. At least it was a nice sunny day, wherever he was.