|Magnum, P.I. is an American crime drama television series starring Tom Selleck as Thomas Magnum, a private investigator living on Oahu, Hawaii. The series ran from 1980 to 1988 in first-run broadcast on the American CBS television network.
According to the Nielsen ratings, Magnum, P.I. consistently ranked in the top twenty U.S. television programs during the first five years that the series was originally broadcast in the United States.
Thomas Sullivan Magnum IV, a private investigator, played by Tom Selleck, resides in the guest house of a posh, 200-acre (81 ha) beachfront estate, known as Robin's Nest, in Hawaii, at the invitation of its owner, Robin Masters, the celebrated-but-never-seen author of several dozen lurid novels. Ostensibly this is quid pro quo for Magnum's services based upon Magnum's expertise in security; the pilot and several early episodes suggest Magnum also did Masters a favor of some kind, possibly when Masters hired him for a case. The voice of Robin Masters, heard only a few times per season, was provided by Orson Welles (one last "appearance" was provided by a different actor, Reid Crandell).
With Magnum living a luxurious life on the estate and operating as a P.I. on cases that suit him, the only thorn in the side of this near-perfect lifestyle on the estate is Jonathan Quayle Higgins III, played by John Hillerman, an ex-British Army Sergeant Major, a (on the surface) stern, "by-the-book" ex-soldier, whose strict ways usually conflict with Magnum's much more easy-going methods. He patrols Robin's Nest with his two highly trained "lads", Doberman Pinschers, Zeus and Apollo. Often as a humorous aside during various episodes of the series, Magnum must bargain with Higgins for use of estate amenities other than the guest house and the Ferrari 308 GTS (e.g., tennis courts, wine cellar, expensive cameras).
The relationship between Magnum and Higgins was initially cool but as the series progressed, an unspoken respect and fondness of sorts grew between the pair, and as such, many episodes dedicated more screen time to this "odd couple" pairing after the relationship proved popular with fans. A recurrent theme throughout the last two seasons (starting in the episode "Paper War") involves Magnum's sneaking suspicion that Higgins is actually Robin Masters since he opens Robin's mail, calls Robin's Ferrari "his car", etc. This suspicion is never proved or disproved.