On the opening night of ''Princess Ida'' at the Savoy Theatre in January 1884, composer Sir Arthur Sullivan (Allan Corduner), who is ill from kidney disease, is barely able to make it to the theatre to conduct. He goes on a holiday to Continental Europe hoping that the rest will improve his health. While he is away, ticket sales and audiences at the Savoy Theatre wilt in the hot summer weather. Producer Richard D'Oyly Carte (Ron Cook) has called on Sullivan and the playwright W. S. Gilbert (Jim Broadbent) to create a new piece for the Savoy, but it is not ready when ''Ida'' closes. Until a new piece can be prepared, Carte revives an earlier Gilbert and Sullivan work, ''The Sorcerer''.