Victoria goes to Paris to visit her sister Carolyn. Carolyn coaxes her reserved sister to go out to a party with her, a secret party. This party is an exclusive invite only event that is held in the underground catacombs. The party is never in the same place twice. They arrive at the party set deep within the labyrinth of underground Paris and soon after wander off with some of Carolyn's friends to a private spot to swim. Victoria becomes irritated with Carolyn and decides to go back to the party. She gets lost on her way back and starts to panic when she hears strange noises coming from the tunnels.
She eventually finds her way back to the party but her relief is short lived when the party is raided by police and she is knocked down by the stampede of exiting party goers. She reaches the gate where she entered but it is locked tight. She ends up spending a night of complete hell lost in the never ending tunnels with a deranged killer at her heels. I really don't want to give any more away than that.
I liked this movie and thought it was a good scare. Maybe it's because I got lost once as a kid and know how scary it can be. I don't know, but I am very partial to these kind of films where the person just doesn't seem to have a way out. The catacombs themselves are quite frightening, skulls embedded in the walls and it's nearly impossible to tell where the sound is coming from. She really loses her grip on sanity, I'm quite sure I would too.