People in an old, dark mansion are menaced by a maniac called "The Black Ace".
| Actor | Role |
|---|---|
 Chester MorrisNeil Broderick | Neil Broderick |
 Vivienne OsborneMartha Winters | Martha Winters |
 Frank McHughClancy | Clancy |
 Allen JenkinsDugan | Dugan |
 Henry StephensonThornton Drake | Thornton Drake |
 Grant MitchellAustin Winters | Austin Winters |
 Charles MiddletonJerry Simons | Jerry Simons |
 Virginia HowellMrs. Quincy | Mrs. Quincy |
 Oscar ApfelAsa Marsden | Asa Marsden |
 Cornelius KeefeHenderson | Henderson |
| GGus RobinsonPompey | Pompey |
 Edward LeSaintCoroner | Coroner |