Riggs and Murtaugh respond to the death of a plastic surgeon, drawing them into a case involving an illegal drug ring run out of a wellness clinic. Things heat up when Palmer (guest star Hilarie Burton) from the DEA and Riggs compete to solve the case first. Meanwhile, Trish and Murtaugh face the emotional challenges of sending their first son, RJ, off to college
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.