The murder of one of Steed's colleagues leads Cathy to a top-secret research establishment where an adulterous member of the staff is being blackmailed, while Steed checks out the local wine shop.
Sort of a cross between the more straightforward plots of the earlier years, and the quirkiness of the later seasons. A decent episode that still holds up very well today.
After viewing the slides, Cathy has a spot of trouble shutting off the projector, prompting Steed to ask if she needs any help.
When Marion brings in Cathy to introduce her to Cliff, she begins speaking before reaching the boom mike, making her first few words almost inaudible.
Later, when Steed goes to leave Cathy's flat, her automatic sliding door does not open when he approaches leading him to issue an "Open sesame!".
