A nun hires Magnum and Higgins to investigate a mysterious and large cash donation made to a parishioner undergoing medical treatment at the church. Also, Jin’s new dog walking business takes a dramatic turn, and Rick nervously prepares to reconnect with Suzy.

A disoriented man hires Magnum and Higgins to investigate a crime he doesn’t remember after he woke up on the beach covered in blood. Also, T.C. is taken aback when Cade’s biological grandmother makes a surprise visit, and Rick’s feelings for Suzy grow stronger as they prepare for the birth of their first child.

Magnum and Higgins investigate the robbery of an elderly man suffering from Alzheimer’s. The ohana tries to help TC overcome a past trauma.

After a high-stakes homicide case falls apart at trial, Katsumoto asks Magnum to help him stop a killer from walking free. Higgins helps Jin Jeong with a mystery of his own.