AC brotherhood question

So I started something called Christians mission (I think) and the game went the VR room and I was running after this girl for a while, finally I stopped and walked up. Nothing happened. So I walked away...nothing happened. Ran away, tried shooting her, stabbing her. No clue what to do and I can't exit the animus. :(

Any idea what I have to do?

So I'm boned? Erg, don't want to restart the system.

Alright, so turns out it was a christina quest that is very, very bugged. If the red loading room of death happens, restart your system and the correct quest will load.