While working on a routine divorce case, Thomas catches a brief glimpse of a woman on a passing boat that he is certain is Michelle, the girl he married during the Vietnam war seven years ago, and whom he previously believed to have been killed shortly afterwards in a bombing raid. All he has of the brisk sighting is some blurred photos he managed to take, and T.C. and Rick, whilst not completely convinced, help as he scours the local area looking for her. But there are several parties that intend to see that Thomas is unable to make contact with Michelle, and the search sees them stumbling into dangerous political territory.

In the conclusion of this feature-length / two-part story, Magnum's desperate search for Michelle faces being forced to a halt after he has been called up for active Navy duty and ordered to testify in Washington. Thomas suspects that is just a political smoke-screen to try and get him off Michelle's trail. Briefly re-united with Michelle, who is married to Vietnamese General Hue, who is involved in delicate negotiations regarding the returning remains of M.I.A.s and P.O.W.s from Vietnam. But Michelle is suspected of being a traitor agent and is in great danger...

First part of what was originally shown as a feature-length story. Nuzo, an old war comrade of T.C. and Magnum's, suddenly arrives in Hawaii, and finds T.C. to warn him that Colonel Ivan, a sadistic Russian agent who once held them captive and tortured them in a P.O.W. camp in Vietnam, is after them. At first, T.C. puts his old buddy's fears down to delayed stress, but it gradually begins to seem that there might be some truth in his claims. Meanwhile, Lt. MacReynolds resigns from the Navy, and Magnum lets him stay with him for a few days, but a fatal accident meant for Thomas - as yet unaware of Nuzo's warnings - adds ground to the fears that maybe Ivan is on the trail after all...

Conclusion of this feature-length / two-part story. As Magnum, T.C. and Nuzo plan to get to Ivan before he kills them, the Navy – inparticular Colonel Greene and Admiral Hawkes – have their own concerns in the situation and questions regarding Mac's death. But things are not as previously thought about Nuzo, and not only is T.C.'s life in great danger, but many other people's too as a result, in part of an assassination plot of a Japanese prince...

Magnum is called back to Naval service by Admiral Hawkes, who has reason to suspect that there is a security leak at his Naval base that is leaking coded information, but can't ask any of his personnel to investigate for any one of them could be the ""mole"" behind the breach. He needs Magnum to root out the mole and plug the leak within three days, when he is due to receive some important submarine manuals written in code, which could be potentially very dangerous if they got into the wrong hands. Thomas' prime suspect is the fiancée of the Admiral's son, but when some stolen classified information is planted in his car, he himself accused of espionage...