Holmes and Watson attempt to break the grip of a ruthless blackmailer of their clients.
Peter Hammond
Jeremy Brett
Edward Hardwicke
Robert Hardy
Norma West
Gwen Ffrangcon Davies
Colin Jeavons
Serena Gordon
Rosalie Williams
Sophie Thompson
Nickolas Grace
Sarah McVicar
David Mallinson
Brian Mitchell
Hans Meyer
Stephen Simms
Granada Television
GBH
