 A Honolulu businessman is found murdered on a land tract he was trying to develop. The case has all the earmarks of a syndicate hit. Five-O traces the dead man and finds that he was, in fact, a former thug who had testified and gone into the Federal witness protection program. But they find this out so easily that McGarrett begins to suspect that the mob had nothing at all to do with the murder -- someone close to the witness, who knew all about his history, killed him and pinned it on the mob. Suspicion soon falls on the dead man s wife and her lover, who were to be the beneficiaries of a $100,000 insurance policy paid by Uncle Sam if the witness was indeed whacked (the money seems like chump change when you look at the lavish mansion where the dead man lived). McGarrett and the Federal agent overseeing the witness protection program plan in Hawaii, who have often been at odds in the past, begin to collaborate in trying to fool the killer or killers into thinking the mob is after them -- because the dead man had a surgically altered face, he could be anyone, including the wife s lover.