Magnum, P.I. (1980)

While Higgins is preparing to direct a selection of pieces from Gilbert and Sullivan's 'The Mikado' to be staged at the Estate, Thomas is hired by an attractive young woman to find her missing brother, who she claims has disappeared after joining a religious cult. The girl has musical experience and agrees to help out with rehearsals of Higgins' production while Thomas seeks out her missing brother, but Thomas uncovers more than he expects and finds himself dealing with a radical political group and an assassination attempt revolving around a visiting cast member of Higgins' production...