House On Haunted Hill
The owner of a horror-themed amusement park arranges an overnight party in an abandoned mental hospital. The location, it turns out, was once the site of horrifying medical experiments. If his guests are brave enough to last the night, he will pay them $1 million, each. The guests want the money. The otherworldly residents have different plans for the soon-to-be terrified (and slaughtered) guests.