 On his first night patrolling an old industrial estate, security guard Nick Ellis discovers all is not what it seems. After being introduced to Bill, a veteran security guard, Nick is expecting a quiet night. However, events take a strange twist when Nick discovers a woman wandering the upper levels of the building. She claims to have escaped from the top floor, where she says people have been holding her against her will. Nick goes to radio it in, but Bill cannot be reached...