A Japanese Samurai warrior brings an antique plate to Hawaii that Robin Masters had purchased. The Samurai is attacked, the plate is stolen and Robin wants TM to recover it.
Two Japanese-Americans who were interned on Sand Island in January 1942 witness two soldiers beating a fellow Japanese internee to death. This incident causes repercussions today.
A single engine light aircraft being flown from California to Hawaii crashes into the tidal pool at the estate. Turns out the pilot is a man from Magnum's war days.
Higgins' half brother, an Irish Catholic priest from Northern Ireland, arrives in Hawaii to confront a British officer who he claims stole an ancient artifact from his church.
Luther Gillis is a private investigator from St. Louis who was hired by the father of a 16-year-old runaway girl to find her. At the same time, Magnum was hired by the girl's mother to find her. Can they work together?
Rick's old friend Waldo Norris is caught trying to break into a guarded building. Waldo claims he is working for an insurance company and is investigating the loss of a valuable figurine.
Rick's 22-year-old sister Wendy arrives in Hawaii. Rick still believes that she is a young, innocent girl and asks Magnum to entertain her while Rick works at the club.
Investigating a series of convenience store robberies, Magnum also comes across a couple of elderly ladies, who live in a broken-down house with other elderly people who are being harassed by a no-good slum lord.
Magnum is in Detroit and TC is using the Ferrari. While driving the car, TC has an accident and injures a bare knuckles fighter and he has to take his place in the ring.
Holly Fox was a DJ in Vietnam admired by all the servicemen including Magnum, TC and Rick. While listening to the radio one day, Magnum hears a voice that he believes is Holly Fox.
It's Christmas time and TC is flying Magnum (dressed as Santa Claus), Rick and Higgins to three different islands. En route, TC is forced to make an emergency landing on an island that the Navy uses for gunnery practice.