A dangerous amnesiac escapes from an asylum, hides in the opera house, and is suspected of getting revenge on those who tried to murder him 13 years ago.
Directed by
H. Bruce Humberstone
Written by
Charles Belden
Boris Karloff
Gravelle
Keye Luke
Lee Chan
William Demarest
Sergeant Kelly
Stanley Blystone
Backstage Cop Who Shoots Gravelle (uncredited)
Benson Fong
Opera Supernumerary (uncredited)
Marc Lawrence
Undetermined Minor Role (uncredited) (unconfirmed)