'Castle De'ath' by John Lucarotti

Steed and Mrs. Peel head off to Scotland to investigate the disappearance of the fish along the English coastline, and the murder of a scuba-diver spy, whose dead body was found to be four inches taller than when he was alive. The clues lead to Castle De'ath, the fate of which is being decided by Ian Dea’Ath, the 35th Scottish laird of the clan, and his cousin, Angus. Mrs. Peel poses as a representative of ABORCASHAATA (the Advisory Bureau on Refurbishing Castles and Stately Homes as a Tourist Attraction), a promotional company that will open the castle to the public, while Steed is a writer researching the 15th laird, Black Jamie. As tension mounts between the two cousins, the two agents encounter a bagpipe-playing ghost, death-traps, and a submarine bay inside an iron maiden…

Patrick Macnee (John Steed), Diana Rigg (Emma Peel), Gordon Jackson (Ian), Robert Urquhart (Angus), Jack Lambert (McNab), James Copeland (Roberton), Russell Waters (Controller)

Directed by James Hill
Produced by Julian Wintle

TX:
UK: 30th October, 1965

Notes:
*Featuring John Steed and Mrs. Emma Peel

* The tag scene: Steed and Mrs. Peel drive off the road and into the water in a huge amphibious vehicle...