Escaped criminal "The Fox" hates Hoppy and a Rurales colonel for imprisoning him and lures Cassidy to Mexico in order to exact his vengeance.
You can now watch In Old Mexico online on the following streaming providers in the United States.
| Directing | Edward D. Venturini | Director |
| Writing | Harrison Jacobs | Screenplay |
| Writing | Clarence E. Mulford | Characters |
| Production | Harry Sherman | Producer |
| Editing | Robert B. Warwick Jr. | Editor |
| Art | Lewis J. Rachmil | Art Direction |
| Camera | Russell Harlan | Director of Photography |
