A bubbly young woman hires Magnum to find her father who, after being missing for over ten years, had sent her a postcard from Hawaii. But her father is involved in some rather shady business, and Magnum isn't the only one looking for him.

When Higgins is involved in a dangerous accident, Magnum's investigation leads to a murder that occurred forty years ago in a Japanese internment camp.

Conned by an old friend, Magnum and TC agree to deliver a set of encyclopedias, not knowing that the knowledge contained within is a large marijuana drop.

Magnum is very enthusiastic about his new project, teaching a class at the University about private investigation. The class is small but interest is great about everyone helps a student investigate the strange behavior of her fiancé.