WriterPaul Huston, Joseph F. Poland Release date1 August 1946 GenresAction Film, Adventure Film, Crime Fiction, Black-and-white CastEdmund MacDonald (Anthony Waldron), Pamela Blake (Shirley Clinton), Danny Morton (Derek Lamont), Virginia Brissac (Cornelia Waldron), Joseph Crehan (Police Chief Dan Blair), Jack Ingram (William Shrag, lead thug) Related Lewis D. Collins moviesThe Scarlet Horseman (1946), The Royal Mounted Rides Again (1945), Lost City of the Jungle (1946), Dennis Moore appears in The Mysterious Mr M and Raiders of Ghost City, Heading for Heaven (1947)
Anthony Waldron intends to steal a new submarine invention from Dr. Kittridge while blaming a fictitious mastermind he calls "Mr. M." To further this plan, Waldron uses a mind control drug he has developed called "Hypnotreme." However, a mystery villain soon appears claiming to be the real Mr. M and starts giving Waldron orders.
Federal agent Grant Farrell, whose brother was killed by Waldron, is dispatched to find the mysterious villain and stop his nefarious plans, teaming up with Kirby Walsh and Shirley Clinton to do so.
Richard Martin as Detective Lieutenant Kirby Walsh
Pamela Blake as Shirley Clinton, insurance investigator
Dennis Moore as Agent Grant Farrell
Virginia Brissac as Cornelia Waldron
Danny Morton (actor) as Derek Lamont, one of Waldron's henchmen
Edmund MacDonald as Anthony Waldron, the original villain
Byron Foulger as Wetherby
Jane Randolph as Marina Lamont, one of Waldron's henchmen
Jack Ingram as William Shrag, the spearpoint heavy (chief henchman)