When a married woman asks Magnum and Higgins to find her lover’s killer because she doesn’t want to expose the affair to the police, they find that the victim wasn’t who he claimed to be. Also, Rick visits Icepick, whose health has taken a turn for the worse.

When Magnum and Higgins are hired by an anxious groom to look into his bride-to-be on the eve of their wedding, what they think is a simple case of cold feet turns into a web of lies and a life-or-death situation for Higgins. Also, TC makes a touching decision on how to help Cade.

A Christmas Eve ransomware attack on the Honolulu Police Department forces Lia to reveal a family secret to Magnum and Katsumoto.

Higgins is in a complicated situation when 12-year-old Ella asks for help cracking a triple homicide that involves her mother. Also, Magnum bonds with Bob, a terminally ill veteran, while volunteering with the No Veteran Dies Alone Program and attempts to reunite him with his estranged family.

Magnum and Higgins are hired to find a missing gamer whose online friends believe he might be in trouble. Jin Jeong enlists the help of TC in a treasure hunt after his ex-partner gets out of prison.

Magnum and Higgins are hired by a University of Oahu dean to quietly investigate a professor who has been accused of having an inappropriate relationship with a female grad student. TC and Katsumoto take Cade and Dennis on a father-son camping trip.