While visiting the circus with his family, Charlie is recruited by the big top's co-owner to investigate threatening letters that he's received.
| Writing | Earl Derr Biggers | Characters |
| Writing | Robert Ellis | Writer |
| Directing | Harry Lachman | Director |
| Production | John Stone | Associate Producer |
| Writing | Helen Logan | Screenplay |
| Camera | Daniel B. Clark | Director of Photography |
| Art | Duncan Cramer | Art Direction |
| Directing | William Eckhardt | Assistant Director |
| Editing | Alex Troffey | Editor |
| Costume & Make-Up | William Lambert | Costume Supervisor |
| Sound | Arthur von Kirbach | Sound |
| Sound | Samuel Kaylin | Music Director |
