The Mysterious Mr. M 1000 startling adventures! 1000 weird sensations! 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. Details Casts Galleries Posters Title The Mysterious Mr. M Release Date 1946-07-23 Runtime 03 Hours 47 Minutes Genres Action Mystery Production Companies Universal Pictures Production Countries United States of America Edmund MacDonald... Anthony Waldron... Pamela Blake... Shirley Clinton... Danny Morton... Derek Lamont... Virginia Brissac... Cornelia Waldron... Joseph Crehan... Dan Blair... Jack Ingram... William Shrag... Dennis Moore... Agent Grant Farrell... Richard Martin... Detective Lt. Kirby Walsh... Byron Foulger... Wetherby... Jane Randolph... Marina Lamont... William Ching... Jim Farrell... Joe Haworth... Donninger... Patricia Alphin... Ms. Buckley... Original Size (1280x720) Original Size (600x900) Original Size (680x1000)