Navy lawyers of the Judge Advocate General's office (JAG) investigate murders, espionage, treason, and other military crimes. Lieutenant Commander Harmon "Harm" Rabb Jr. is the son of a decorated Navy pilot who is still M.I.A. in Vietnam. Harm was a Navy flyer himself until a devastating plane crash. He took up law and joined JAG. Marine Major Sarah "Mac" MacKenzie is a JAG lawyer who faces the challenges of her missions while also dealing with personnel who respond to her gender instead of her uniform. Helping them with their mission is Navy Lieutenant Bud Roberts, a young lawyer who often often surprises his superiors with his knowledge, and his wife, Lieutenant Harriet Sims, who keeps the office running smoothly. Admiral Chegwidden is their no-nonsense boss, a former Navy Seal.