On a stormy night, young Jim, who transports a luxury car from Chicago to California to deliver it to its owner, feeling tired and sleepy, picks up a mysterious hitchhiker, who has appeared out of nowhere, thinking that a good conversation will help him not to fall asleep. He will have enough time to deeply regret such an unmeditated decision.
Veteran buttoned-down LAPD detective Roger Murtaugh is partnered with unhinged cop Martin Riggs, who -- distraught after his wife's death -- has a death wish and takes unnecessary risks with criminals at every turn. The odd couple embark on their first homicide investigation as partners, involving a young woman known to Murtaugh with ties to a drug and prostitution ring.
A hard-nosed cop reluctantly teams up with a wise-cracking criminal temporarily paroled to him, in order to track down a killer.
Vengeance drives a tough Detroit cop to stay on the trail of a power hungry auto magnate who's systematically eliminating his competition.