Plot hole: Every ghost that we see in the house looks the way they did when they died, for example the girl from the film's intro is seen without skin on her face, which happened to her before she died. However, in the final scene when we see Simon's ghost joining them, he looks completely normal, when he should have had a throat slit wound and the carved markings on his skin. (01:31:20)Purple_Girl
Simon McNeal: There is something going on in this house, all right? The first time upstairs, yeah, I faked it. But the second time, that was real. That was something way beyond a few pieces of charcoal. Something way beyond what a guy in a lab coat will ever tell you.
Mary Florescu: I thought you were smarter than this, Simon. I thought, for a moment, you were for real.