When three people wind up trapped in an elevator, it seems like a mere nuisance at first. But with no light and little hope of help arriving, the situation turns tense -- then becomes a nightmare when one of them is revealed to be a serial killer. As nerves fray and emotions intensify, the ordeal devolves into pure animal survival. Amber Tamblyn, Aidan Gillen and Armie Hammer star in this unnerving psychological thriller.