When an Army ranger goes missing after returning from deployment, Magnum learns of the traumatic news he received upon arriving home and must find him before survivor's guilt consumes him. Also, Higgins and Ethan solve the case of a missing engagement ring while on a mini-break, and Katsumoto tries spending quality time with his teenage son.

When a Marine Corps vet's SUV is stolen with her service dog inside, Magnum and Higgins must find the car, the dog and the car thief who they believe may be an escaped kidnapping victim. Also, when TC is sued by a disgruntled customer, he asks Rick and Jin to help prove that he's being scammed.