Riggs is reunited with childhood friends and comes to realize they might be mixed up in the robbery-hugging case he and Murtaugh are investigating. Meanwhile, Murtaugh finds a joint stashed in his kitchen that he brings to Scorsese for testing in effort to bust one of his kids.
When Texas cop and former Navy SEAL Martin Riggs suffers the loss of his wife and baby, he moves to Los Angeles to start anew. There, he gets partnered with LAPD detective Roger Murtaugh, who, having recently suffered a "minor" heart attack, must avoid any stress in his life.
From the moment the brash and impulsive Riggs meets prudent, by-the-book Murtaugh, it seems as if this partnership is doomed. But after their first case together, both realise this arrangement might just work out after all - if only Riggs doesn't get them killed first.