Magnum returns from a case to find that Higgins' old Army commander is staying on the Masters estate, under tight security, until some I.R.A. members he helped capture are tried. Two secret intelligence agents hire Magnum to protect the brigadier and foil assassins out to kill him before the terrorists' trial, but the “need to know” basis the agents insist on operating by only serves to complicate matters for Magnum.

Higgins' half brother, an Irish Catholic priest from Northern Ireland, arrives in Hawaii to confront a British officer who he claims stole an ancient artifact from his church.