In Philadelphia, Detective Bowden is still grieving for his wife and son, killed in a hit-and-run five years ago. A suicidal person jumps off from the top of a skyscraper onto a truck, and Bowden is sent to investigate. Meanwhile five strangers are trapped in an elevator in the building where the jumper committed suicide. The communication radio in the elevator is broken but the guards, Lustig and Ramirez, observe the individuals via CCTV as events unfold. Having been trapped for some time, tensions are high, so Lustig calls the police and Detective Bowden assumes the case. Without being able to contact the individuals he tries to work out who they are and realizes he can only account for four of them. Time is running out for the occupants of the elevator as Bowden realizes he has to get them out quickly.