The trailer for the film Insidious uses various techniques to set up suspense and mystery. It introduces the story of a family whose son enters a comatose state and becomes possessed by ghosts. Throughout the trailer, various unanswered questions are posed to pique the audience's curiosity. Tension is built through the use of a slow musical score that gradually increases in pace, as well as dark lighting and ominous diegetic sounds. The trailer effectively establishes the psychological horror genre through its use of mise-en-scene, including creepy props and a seemingly normal family home that becomes terrorized.