Maddie Curtis and her friends Lilly and Suzanne are ready for a great Halloween night. They're going to a party thrown by their friend Angela at the notorious Broussard Mansion in New Orleans. Over eighty years ago, six people disappeared from the mansion without a trace – and the owner, Evangeline Broussard, hung herself.

The dark history only serves to enhance the Broussard Mansion's appeal on Halloween. At the decadent, out-of-control party, Maddie and Lily run into their exes, Colin and Dex, while Suzanne parties it up. Good times end, however, when the police bust up the party. After the rest of the guests leave, Angela, Maddie, Lily, Dex, Colin, Suzanne and their friend Jason discover a horrible secret. Their cell phones don't work. The mansion gates are now mysteriously locked. Soon it becomes clear that supernatural forces are at work at the Broussard Mansion, and that there may be more to the tale of Evangeline Broussard than anyone knew.

It turns out that the Broussard Mansion is home to demons that need to possess seven vessels to break free of an ancient curse. One by one the guests fall victim, transforming into hideous creatures. Only Maddie, Colin and Jason remain – but can they make it through the night and keep evil forces from spreading into the world?