Sherlock Holmes(Arthur Wontner) and Dr. Watson (Ian Fleming) are lured out of retirement to investigate a mysterious murder at Birlstone Castle. They discover that a group of coalminers calling themselves The Scowlers are caught up in the plot, along with the treacherous Professor Moriarty (Lyn Harding). Holmes must battle wits and might with Moriarity and an American gangster to find the murderers and save The Scowlers from destruction. Stylishly shot with thrills and mystery at every turn, this fourth film in a series of five, with Arthur Wontner as Sherlock Holmes, is one of the best.

An early English adventure-mystery based on the famous works of Sir Arthur Conan Doyle, particularly "The Valley of Fear." Film is a forerunner to the U.S. series which followed in the 1940's.