Bullard asks Barnaby to investigate the disappearance of a friend's daughter who was a member of the Oblong Foundation, a cult based at Malham Hall. Jones goes undercover as a new recruit to solve the mystery, but he and Barnaby soon start digging into an old case involving the death of a couple in a boat explosion, which could be linked to the missing woman.
With Will Knightley, Kevin Doyle, Holly Aird, Barbara Flynn and John Woodvine
Quest roles:
Sophie Stanton(Brenda Buckley), John Woodvine(Sir Harry Chatwyn), Will Knightley(Andrew Turner), Kevin Doyle(Paddy Powell), Richard Albrecht(Mr Oliver), Heather Tobias(Mrs Oliver), Holly Aird(Paige Burrows), Josephine Butler(Freddie Raft), Paul Hilton(Dominic Segal), Christine Bottomley(Blaze Leadbetter), Simon Day(Combover Guy), Charity Wakefield(Ruth Lambert), Tom Fisher(Crusty), Francesca Hunt(Susan Crane)