The Mysterious Mr. M
An evil scientist known as "Mr. M." uses a drug he has developed called "hypnotreme" to help steal submarine equipment. Federal agent Grant Farrell is dispatched to find the mysterious villain and stop his nefarious plans.
- Genre: Action, Mystery
- Studio: Universal Pictures
- Keyword: mind control, memory loss, movie serial
- Cast: Edmund MacDonald, Pamela Blake, Danny Morton, Virginia Brissac, Joseph Crehan, Jack Ingram