Continuity mistake: When the main character goes to check the place where the dead bodies lie, after having seen the red light flash, the rope above the supposedly dead body is still swinging. If you keep watching it you can see that it keeps moving with the same frequency.
Katherine: Oh my god.
Martin Bells: This just doesn't happen! This is not happening! Cray, why are you doing this? What the hell are you doing?
Inspector Thomas Cray: Stop asking for the "how" and "why" Martin.