good concept, bad script

great Idea, really good start, good actors!....but...there is no real story.... the movie is quite interesting until the girl finds out she is locked in and the guy won't let her go.... then actually nothing happens... they hardly even talk... she only begged one time to get free... the rest of the movie she almost stays silent. And we also don't find out why the (really attractive) guy can't have a girlfriend under normal circumstances.
If there script only had been better figured out!