by Roger Marshall
Designed by David Marshall
Directed by Bill Bain
Steed attends the dreary funeral of John Benson, an old secret service colleague, in rain-drenched Tinbey, Cornwall, conducted by Rev Adrian Wyper (George Benson), and raises the suspicions of Roy Hopkins (Philip Locke).
Hopkins and Dr Macombie (John Le Mesurier) finalise a contact with Benson (Robert Morris) for safe disposal of his father. Hopkins promises Macombie another £20,000 a year - another client. Steed visits Benson on his yacht and grills him about his father's death. Steed tells Cathy he doesn't believe Benson, and shows her some death notices for Tinbey - 3 from London in the past month, Tinbey being a ghost village since the tin mine shut down. Benson goes to Macombie and is told not to worry, an exhumation can find nothing, but was followed... Cathy visits the graveyard and photographs the headstones, meeting the vicar who reveals the churchyard used to have a mandrake root and now has deadly nightshade. In the church, she meets Hopkins who has brought Mrs Turner (Madge Ryan) to see the vicar to buy a plot for her 'ailing' husband. Outside, Cathy overhears Hopkins tell the Cockney sexton (Jackie Pallo) they're in business again, and if he sees Cathy snooping around, they'll make it a double booking.
Mrs Turner writes a £5,000 cheque to Mandrake Investments and is given a bottle containing a fatal dose of poison. Steed tracks Hopkins to a Christmas cracker business, where Judy (Annette André) reveals he's seldom there - he inherited the business after his uncle died - in Cornwall! Cathy's catalogue of 11 recent graves turns up 9 in 'Who's Who', 7 of which left estates in excess of £100,000; 8 of the 11 were treated by Macombie so she visits him, feigning an injury, and frightens him by saying she lives near Tinbey and was a friend of John Benson. Macombie immediately phones Hopkins, wanting to back out again. Later, Steed breaks into Macombie's through a side door Cathy had unlocked while Macombie made up some eye drops and goes through his case notes. Cathy meanwhile has returned to Cornwall and is set upon by the sexton as she collects soil samples. The sexton dispatched, the vicar appears and holds her at gunpoint...
Steed returns to the cracker factory and learns of Mandrake Investments from Judy. He then visits Benson and roughs him up - Macombie's notes included a prescription on a day John Benson was in Beirut. Cathy returns to the church (the vicar had a toy gun) with the evidence - the soil analysis shows the earth is thick with arsenic, which the vicar attributes to the proximity of the tin mine, but is dismayed when he realises he's been burying the victims of murders through Hopkins and Macombie. They formulate a plan...
At the end of the internment, Steed and Cathy stop Hopkins, Macombie and Mrs Turner from leaving, informing them Turner hasn't been buried, he's in the mortuary, and a post-mortem conducted an hour ago proved acute arsenic poisoning. Hopkins calls the sexton over to help, but he's on Cathy's side since losing the fight (and being bribed) and takes the villains into custody. It starts to pour with rain again...