The Mysterious Mr. M (1946) is a Action, Mystery film that follows 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. The Mysterious Mr. M is not currently listed with streaming providers in your selected region, but availability can change over time. It has a user rating of 5.2 out of 10 from 3 votes. Fans of action movies may also want to explore similar titles below.