Dir: Roy William Neill
Starring: Basil Rathbone and Nigel Bruce
Holmes and Watson have to crack a secret code in order to prevent a new weapon from falling into the hands of Nazi Germany
Sherlock Holmes and the Secret Weapon is the fourth in the Basil Rathbone / Nigel Bruce series of 14 Sherlock Holmes films which updated the characters created by Sir Arthur Conan Doyle to the then present day. It features a couple of shots of trams passing on Westminster Bridge.