Murtaugh and Riggs investigate the mysterious death of famous singer Shaye's bodyguard. Murtaugh turns to his daughter, a fan of the singer, to learn more about Shaye's background and uncover the possible suspects. Meanwhile, Riggs learns the responsibilities that come with being in a relationship with help from Murtaugh.
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.