Magnum and Higgins must find Kumu when she's kidnapped by an injured man accused of killing his wife.

Magnum and Higgins work a stalking case involving a man with a past in espionage. Also, Ethan asks Higgins to join him on an extended trip for Doctors Without Borders just as Magnum starts to open up to other possibilities.

When a woman hires Magnum and Higgins to locate a man she met briefly at a coffee shop and felt a spark with, they learn that he is hiding a big secret. Also, Higgins keeps a secret of her own after she has a romantic dream about Magnum.

Magnum and Higgins take a major step forward in their relationship. At the same time, the past comes back to haunt them when a previous suspect becomes their client. TC aims to scale up Island Hoppers. Rick gets a new business partner.