Magnum is hired by a beautiful Chinese antiques dealer that he's making a play for, to protect a precious ancient vase, ""the Soul of Soong"", until it's buyer arrives in Hawaii to collect it. But unbeknown to him, the priceless ornament is wanted by a Tong gang from the girl's home country, and a deadly martial arts assassin who can kill in the blink of an eye is hot on the trail...

As he continues his memoirs, Higgins recalls the spring of 1976, when old friend from Sandhurst, David Worth, arrives in Honolulu to attend the funeral of a mutual friend. Insisting that his name is Stanley Sigerson, Sherlock Holmes's most frequently used alias, and that Higgins is Watson, Holmes's faithful friend, David firmly believes that their friend was murdered by none other than Moriarty, Sherlock Holmes's arch-nemesis. In the name of friendship, Higgins indulges David in his investigation, even though his suspicion that David is insane is borne out, and is shocked to discover that David's assertion that their friend was murdered was absolutely correct.

Mac's latest shady money-making scheme has landed him in trouble with the Japanese Yakuza, so he convinces Rick to buy a sailboat from him, complete with a crew of three Japanese women who barely speak a word of English. Rick is furious when Mac skips town just before the boat is impounded because Mac didn't own it in the first place, leaving Rick unable to repay Ice Pick the $20,000 he borrowed to buy the yacht, now that he can't make the money he planned by renting the boat out for charters. To get Rick's money back and keep the Yakuza and Ice Pick from doing him harm, Thomas sets out across the mainland to track down Mac.