What is David Tennant doing here?

He's dressed as the doctor...but he doesn't play that character any more...

Princess takes his hand and they walk past Octavia and I.

I swear to God as they pass, David mouths 'Help me'.

Octavia is still droning on.

"Y'know, OC," I smile, "I think I'm going to go to class."

I don't wait for her to reply, I just zoom off after Princess and David.

Princess eventually releases his hand and goes into a classroom.

"David!" I call out, as he begins to wander off.

He doesn't respond.

He just shoves his hands into the pockets of his brown coat and whistles.

I begin following him, trying to do it quietly.

What the hell is he doing?

"DAVID!" I yell after him.

He doesn't acknowledge me.

He brings out what looks like a prop of the sonic screwdriver.

This guy...

This guy isn't David Tennant...

"DOCTOR!" I yell.

Success!

He instantly whips around, sending his coat flying around his legs.

"Aha!" He points to me, "You got my message."

So he WAS mouthing something.

"Uh...what?"

"You're not from this universe, are you?" He asks.

"I have no idea!"

"Look, I'm not from here, I've been sent here in some sort of...mad time-shifting world-changing vortex."

"Uh..." What? "Who are you?"

"I'm The Doctor." He lowers his eyebrows, "You just careered down that corridor yelling my name..."

"DOCTOR WHO?" I burst out laughing.

He's totally gotta get this one, right?

He's...not laughing.

Uh...

"I'm going to go to class." I say.

Wait, what?

I didn't want to say that!

"Bye!"

NOOOOOOOOOO!