Most visitors never think about what goes on behind the scenes of a professional haunted house. The fear you feel before the first scare is engineered. The actor who appears at exactly the right moment is trained and assigned. From C.H.A.O.S. safety certification to year-round off-season investments, these are five behind-the-scene secrets professional haunted attractions keep to themselves.

The Nightmare Factory earns 5 C.H.A.O.S. safety certifications, setting the standard for haunted attraction safety ahead of the biggest season in the Factory's history.

The jump scare has a longer and stranger history than most people realize. It started with a $150,000 B-movie in 1942, was nearly killed by a studio executive who hated it, and went on to earn four million dollars and reshape an entire genre. Here is where it came from, why your brain cannot stop it from working, and what it looks like inside 66,000 square feet of purpose-built darkness.