The House on Haunted Hill

Jeff is assigned two cases at once. He sends Marty to investigate the first, a supposedly-haunted mansion, Merston Manor, for a Mr. Webster. He takes the second, a diamond theft from Mortland, himself. The sales director of Mortland, Mr. Previss, threatens Jeff, then offers him £5000 to close the case. Jeff attempts to expose Previss, but Previss reveals he has kidnapped Jeannie's sister Jenny to make sure he cooperates.

Webster contacts Jeff to ask why Jeff's car, which Jenny was using, is parked outside the Manor. Jeff realizes that Jenny has been taken there, and joins Marty to investigate. They find out that the house is a front for a diamond-fencing organization. The criminals attack and restrain Jeff with Jenny. Marty finds a psychic group meeting close by and manages to ask for help through one of the members, who attend the manor and rescue Jeff.

• Mike Pratt as Jeff Randall
• Kenneth Cope as Marty Hopkirk
• Judith Arthy as Jenny
• Keith Buckley as Lattimer
• Jeremy Burnham as Walter Previss
• George A. Cooper as Webster
• Terry Duggan as Jackson
• Peter Jones as Frederick P. Waller
• Dermot Kelly as Henry Mace Horsfall
• William Kendall as Col. Jarrett
• John Kidd as Simpson
• Duncan Lamont as Langford
• Garfield Morgan as Carlson
• David Sinclair as Smith

Annette Andre does not appear in this episode, as she was ill at the time of recording. Her character Jeannie Hopkirk is explained away as being on holiday, and Jenny (Judith Arthy), Jeannie's sister, who first appeared in "A Disturbing Case", is standing in for Jeannie as Jeff Randall's secretary.

Moreover, following the episode's prologue, Judith Arthy is named in the title sequence in place of Annette Andre, although no image of Arthy is used. This is the only episode in the entire series where the title sequence is different.

The episode was released on VHS and several times on DVD with differing special features.

• "The House on Haunted Hill" at IMDb