Directed by Harald Reinl, Der Würger von Schloß Blackmoor is a Bryan Edgar Wallace adaptation. Not Edgar Wallace, but his son. He wrote books of his own, adapted his father’s stories for movies and even had some of his stories turned into films like this and The Phantom of Soho and The Dead Are Alive. There’s also a rumor that he was an uncredited contributor to the script of The Cat o’ Nine Tails.

The killer in this is strangling people on a British estate. However, not only does he do that, he then brands an M into the foreheads of those he murders and then decapitates them. Well, maybe he likes to make sure that they’re dead.

The masked killer shows up after a party during which Lucius Clark (Rudolf Fernau) announces that he will be knighted. The hooded strangler accuses him of stealing diamonds and killing Charles Manning, then claims that he will kill until he gets what he wants. He may also only have nine fingers, and the police, Lucius, and his niece Claridge (Karin Dor, who would play Helga Brandt in You Only Live Twice and is also in The Torture Chamber of Dr. Sadism and Los Monstruos del Terror) must solve the case before more are killed.

This is part of the Terror In the Fog box set and has extras including a new introduction by genre film expert and Video Watchdog founder Tim Lucas and audio commentary by Kevin Lyons and Jonathan Rigby. You can get it from MVD.