Sherlock Holmes and the Voice of Terror

In England at the start of World War Two, mysterious wireless broadcasts warning of acts of terror in England are heard over the BBC, baffling the Defense Committee. Brought in to help solve the mystery is Sherlock Holmes (Basil Rathbone), who uses an oscilloscope to determine that "The Voice of Terror" is actually recorded on phonograph records in the UK and broadcast from Germany. With the support of British troopers, Holmes captures Meade, a German spy, and reveals that Sir Evan Barham, a high-ranking official, was impersonating "The Voice of Terror" - an impostor posing as a former German prisoner who had an uncanny resemblance to the real man, whose scar is revealed by careful observation.