Episode

The Problem of Thor Bridge

Cast
Jeremy Brett as Sherlock Holmes
Edward Hardwicke as Dr. John H. Watson
Niven Boyd as Marlow Bates
Dean Magri as Billy
Andrew Wilde as Sgt. Coventry
Philip Bretherton as Joyce Cummings
Catherine Russell as Grace Dunbar
Stephen MacDonald as Mr. Ferguson
Daniel Massey as J. Neil Gibson
Celia Gregory as Maria Gibson
(uncredited) as the two Gibson children