William Troubshaw, an old adversary of Higgins who had made his life misery at school, married the girl he once loved, and eternally the bane of Higgins' life, has recently moved to the islands with his family, and they two old rivals are scheduled to compete against each other in an upcoming fencing tournament. But during the duel, Troubshaw is suddenly killed in seemingly a freak accident, when Higgins' foil sets off his hit indicator, causing him to be electrocuted. Higgins becomes suspect for murder when his fingerprints are found on the rewired scoring box. Magnum is certain that Higgins couldn't have been responsible for the killing, and sets about finding the real culprit behind the death, but the evidence and motives are stacked up against Higgins, and for some reason, he is refusing to call upon Robin Master's top lawyers and is just going along with the allegations...

Carol persuades Magnum to do some work for her, gathering additional evidence for the big murder case of a man accused of killing his wife that is due to come up in court in a couple of days. The only witness of the woman's death is her young daughter, but Thomas faces a crisis of conscience over just what to and what not to present as evidence in the court-room that could ensure the conviction of the violent accused killer... Meanwhile, Higgins, tired of Magnum's slackness around the Estate, has taken use of the Ferrari away from him, so Thomas must find a new vehicle to get around in...

A reluctant Magnum is hired by Ms. Jones – the clerk at the Hall of Records who often aggravates him with excessive red tape – to help her find her husband Ray. He is an expert computer programmer who has disappeared after completing work on a valuable new Artificial Intelligence formula, which could potentially be dangerous if it falls into the wrong hands...