Vietnam Veteran Turned Private Investigator Thomas Magnum Works As Head Of Security On The Luxurious Hawaiian Estate Of Wealthy, But Absentee Owner Robin Masters. With The Mansion And Its Amenities, Including A 308 Gts Ferrari, At His Disposal, Magnum Investigates His Cases While Clashing With The Estate's Strict Caretaker, Jonathan Higgins, An Ex-british Army Soldier.