Filmed entirely on location in Hawaii, this popular long-running cop show followed Jack Lord as he played Steve McGarrett, the tough-as-nails, cool-as-ice head of an elite state police unit that investigated "organized crime, murder, assassination attempts, foreign agents, and felonies of every type." James MacArthur played his second-in-command Danny ("Danno") Williams, with local actors playing members of the Five-O team.