Basil Rathbone character Sherlock Holmes
Nigel Bruce character Doctor Watson
Marjorie Lord character Nancy Partridge
Henry Daniell character William Easter
George Zucco character Heinrich Hinckel aka Richard Stanley
John Archer character Naval Lt. Pete Merriam
Gavin Muir character Mr. Lang, government agent
Edmund MacDonald character Detective Lt. Grogan
Don Terry character Howe
Mary Gordon character Mrs. Hudson
John Burton character Army Inspector (uncredited)
Bradley Page character Cady
Clarence Muse character George
Mary Forbes character Mrs. Pettibone
Holmes Herbert character Mr. Ahrens
Thurston Hall character Sen. Henry Babcock
Ian Wolfe character Antiques Store Sales Clerk
Gerald Hamer character Alfred Pettibone
Gilbert Emery character Sir Henry Marchmont
Margaret Seddon character Miss Pringle
Mary Field character Party Pianist
Colin Kenny character Hotel Doorman
