The Avengers - Season 3 - Eps 21: Build a Better Mousetrap
What does Cathy joining a motorcycle gang, two elderly ladies who own a watermill and claim to be witches, and all of the clocks stopping at a local atomic research station have in common? They're all present in Brian Clemen's first great step into the bizarre.
About The Avengers

Title: The Avengers
First Air Date: 1961-01-07
Last Air Date: 1969-05-21
Status: Ended
Rating: 7.729/10 (from 140 votes)
Language: EN
Seasons: 7
Total Episodes: 161
Network: ITV1
Genres: Action & Adventure, Crime, Sci-Fi & Fantasy
Production Companies: Associated British Picture Corporation, Associated British Corporation, ABC Weekend Television
Synopsis
A quirky spy show of the adventures of eccentrically suave British Agent John Steed and his predominantly female partners. Jonathan Steed - an urbane, proper gentleman spy - teams with various assistants throughout the series' run, including Dr. David Keel, Cathy Gale, Emma Peel and Tara King, to repeatedly save the world from diabolical schemes plotted by equally diabolical evil-doers (among them robots and man-eating monsters).
Cast

Patrick Macnee
John Steed

Linda Thorson
Tara King

Ian Ogilvy

William Lucas