A decorated former Navy SEAL who, upon returning home from Afghanistan, repurposes his military skills to become a private investigator in Hawaii.

Magnum, flooded with memories of his tour in Afghanistan, helps his fallen friend’s brother search for a now-grown Afghan boy who may have been a victim of trafficking.

Magnum is called up from the reserves for a top secret mission, but his friends are stunned when they learn that the mission is a lie and Magnum has been set up.

Magnum and Higgins weigh the risks of pursuing a relationship. Rick juggles being a new father and running La Mariana. Katsumoto tries to figure out his next move.

Magnum and Higgins go undercover as lifeguards in order to solve a murder. Jin Jeong wins a storage unit auction and enlists the help of Rick and TC upon finding a stolen military medal.

Katsumoto takes a job providing security for a chart-topping K-pop star. Higgins and Rick find themselves in peril while trying to help Rick's friend. Magnum harbors suspicions about Capt. Greene's death.