The Season 10 finale of NCIS: Los Angeles , titled originally aired on May 19, 2019. It is the concluding chapter of a high-stakes crossover event featuring characters from the original JAG series. Episode Summary: "False Flag" (S10, E24)

David James Elliott (Harm) and Catherine Bell (Mac) Where to Watch

In this intense finale, Callen and Sam are aboard the USS Allegiance, working alongside (David James Elliott) to uncover a group of ISIS sympathizers planning a terrorist attack. Meanwhile, Hetty enlists the help of Lieutenant Colonel Sarah "Mac" MacKenzie (Catherine Bell) to assist the rest of the team in Los Angeles. Key Plot Points: