Sherlock Holmes gets the clues he needs to solve a murder, and to prevent another one from occurring, when he finds out that a doctor owns a poisonous snake--the deadly swamp adder. Filmed on the expensive sets leftover from the movie Joan of Arc at Hal Roach Studios in Culver City and produced for the "Your Show Time" series, the short has been released as a solo feature on many DVDs that chronicle classic Sherlock Holmes films..
Arthur Shields
as The Bookshop Man
Alan Napier
as Sherlock Holmes
Evelyn Ankers
as Miss Stoner
Melville Cooper
as Dr. John H. Watson
Edgar Barrier
as Dr. Grimesby Roylott
Richard Fraser
as John Armitage
Gail Roberts
as Jean Stoner