A man with multiple personality disorder is being held captive by a murderous cult or his own personalities. He must rescue a girl who may or may not exist and escape.

This is a different take, but make of it what you will:

"When a lone schizophrenic experiences relapse he must regain trust from the girl of his dreams whom holds partial control of his ever hostile subconscious."

This is a different take, but make of it what you will:

"When a lone schizophrenic experiences relapse he must regain trust from the girl of his dreams whom holds partial control of his ever hostile subconscious."

A man with multiple personality disorder wakes from a blackout and learns he and a girl he can hear in an adjoining room are being held by people hiding from view who plan to kill them.

I am resisting put the obvious ?they must escape before this happens?. I think that goes without saying.