Magnum is searching for a spy who's been selling computer information from a large corporation. The president of the company tells him he suspects his wife of having an affair and asks him to follow her. Magnum is distressed to find her having an intimate dinner with one of his best friends, Rick.
The Ferrari, with an unconscious and injured Magnum in it, is found at the bottom of a cliff. Magnum is rushed to a hospital but when he regains consciousness is found to have amnesia and cannot remember what happened.
Someone is trying to kill professional football quarterback Dorsey Bramlett who was the backup quarterback for Magnum at the U.S. Naval Academy. Bramlett contacts Magnum and asks Tom to be his bodyguard.
Magnum, TC and Nuzo had escaped from a North Vietnamese POW camp during the Vietnam War. Nuzo returns to Hawaii and tells TC that the brutal Russian Colonel who was at the camp has returned to the U.S. and is going to kill him.