Frank Murphy (Roy Scheider) is a Los Angeles Police Department (LAPD) air support division officer and troubled Vietnam War veteran with post traumatic stress disorder (PTSD). His newly assigned field partner is Richard Lymangood (Daniel Stern). The two patrol Los Angeles at night and give assistance to police forces on the ground.
When Lymangood first encounters Murphy, the latter is conducting what he describes as a personal test. As Murphy explains to Lymangood later, he has read somewhere (screenwriters Don Jakoby and Dan O'Bannon do not specify the source) that "if you really think you're going over the edge, the first thing you lose is your sense of time. With your eyes shut, you can't tell twenty-five seconds from five!"
Directed by John Badham
Produced by Gordon Carroll
Phil Feldman
Andrew Fogelson
Written by Dan O'Bannon
Don Jakoby
Starring
Roy Scheider
Warren Oates
Candy Clark
Daniel Stern
Malcolm McDowell
Music by Arthur B. Rubinstein
Cinematography John A. Alonzo
Edited by Edward M. Abroms
Frank Morriss
Roy Scheider as Officer Francis McNeil "Frank" Murphy
Malcolm McDowell as Colonel F. E. Cochrane
Daniel Stern as Officer Richard Lymangood
Candy Clark as Kate
Warren Oates as Captain Jack Braddock