Hell House LLC

A documentary crew investigates the deaths of a haunted-house-attraction company whose opening night in a converted upstate hotel ended in a mass-casualty event nobody survived to explain. The company's own setup footage is the evidence.

Stephen Cognetti made it for almost nothing and it works because of one very good idea: the crew are professionals who build fake scares for a living, so the horror is them slowly realising that some of the mannequins and effects in the hotel are moving on their own and were not part of the design.

The basement clown sequence is one of the best-regarded scares in modern found footage, and the film's restraint, holding figures in the background of shots the characters are not looking at, is expert.

It spawned a whole series. The first is the one to see, and it is a genuine word-of-mouth success on streaming.