Sylvester Stallone stars as Marion Cobretti, aka Cobra, who is sent to investigate a spate of random murders happening in the city. The "murderer" turns out to be a covert group of trained assassins with ties to the police force. However, they make a big mistake in leaving a witness to their crime alive. To fulfill his mission and protect the witness, Cobra must become a one-man army against the legion of assassins.