Castle Sinister (1948)

A British agent journeys to the isolated Glennye Castle in Scotland amidst wartime chaos to uncover the truth behind a baffling murder linked to a masked specter. As he delves deeper into the castle's secrets, he must unravel the identity of the enigmatic phantom and its connection to German forces. Suspense and intrigue weave through this atmospheric tale, as the agent races against time to solve the mystery before it spirals further into danger.