"Hell" of course being the back section of Mr. Reed's house, which includes a chapel he built himself, as well as two staircases — one marked "belief," the other "disbelief" — leading down into the darkness. These staircases become the focal point for a religious battle of wits, as Mr. Reed tests the Sisters' faith to its limit.

The official logline for Heretic reads, “Two young missionaries are forced to prove their faith when they knock on the wrong door and are greeted by a diabolical Mr. Reed (Hugh Grant), becoming ensnared in his deadly game of cat-and-mouse.”