This movie is an adaptation of Gilbert and Sullivan's comic operetta of the same name, with parts of other of their operettas stirred in. Frederic has fallen in love with sweet innocent Mabel. Yet his vocation is an impediment to their union. Perhaps the situation can be rectified by his old nurse, Ruth, who made a dreadful blunder years before. A highlight is the song/dance A Policeman's Lot is Not a Happy One.