Sherlock Holmes
Doctor Watson
Nancy Partridge
William Easter
Heinrich Hinckel aka Richard Stanley
Naval Lt. Pete Merriam
Mr. Lang, government agent
Detective Lt. Grogan
Howe
Mrs. Hudson
Cady
George
Mrs. Pettibone
Mr. Ahrens
Sen. Henry Babcock
Antiques Store Sales Clerk
Army Inspector (uncredited)
Alfred Pettibone
Sir Henry Marchmont (uncredited)
Miss Pringle (uncredited)
Party Pianist (uncredited)
Hotel Doorman (uncredited)
Mrs. Ruxton
