Season 4 - Episode 4 "Thirteen"; The episode revolves around a man killing people with the same first names as the thirteen apostles (Mary Magdalene being the 13th), and killing them in a similar fashion in which the apostles died. At one point, Colby and David find a box with a mannequin's head in it. This is a reference to the film 'Se7en', in which seven people are killed for committing one of the seven deadly sins. The film ends with the main characters finding an actual head in a box.