Veteran police detective Roger Murtaugh (Danny Glover) is only days away from retiring when he and his tough partner, Martin Riggs (Mel Gibson), are roped into an important internal affairs case. Working with the beautiful, no-nonsense Sergeant Lorna Cole (Rene Russo) and aided by the shifty informant Leo Getz (Joe Pesci), Murtaugh and Riggs begin to close in on a black-market weapons operation involving corrupt cop and arms dealer Jack Travis (Stuart Wilson).