Psycho follows some thriller conventions such as fast pacing scenes like Marian's murder, having a disadvantaged hero in Sam versus the villain Norman Bates, and a villain that causes problems for the hero. However, it also challenges conventions by switching heroes and blending elements of thriller and mystery genres. Hitchcock uses suspense through music and Norman's unresolved fate at the end. He also employs the McGuffin device of the stolen money to drive the plot forward despite its lack of relevance to the overall story.