The Diabolical Masterminds of Series 6 (1968-9)
Disgruntled British Army officer Hansing plans to take over the country by faking a terrorist bomb, requiring the evacuation of London and the disarming of the device - but he is in fact installing his own nuclear device, supplied by Eastern Bloc insurgents. His brigade rampage through town, summarily executing anyone they find on the streets, but they hadn't expected that Steed and Tara would have slept through the evacuation order and would be on hand to stop his plan when some journalists uncover the truth.
The villainous Earle, Stanley and Gardiner (hur, hur) blackmail society bigwigs, and frame them for murders if they don't come across with the goods - they get a bit confused, though, and often frame them while blackmailing them, but it's an enjoyable romp nonetheless.
The staff of a large country retreat in a village atmosphere trap people at the hotel so they can never leave in a pastiche of McGoohan's "The Prisoner" - business partners and secret agents can hire the hotelier to keep people against their will, and dispose of them if need be too.
The hypnotic Kreer brainwashes Steed so he can't see Proctor, who follows him around, occassionally thumping him in an attempt to unhinge Steed and destroy confidence in British Security. We've seen it all before...
MI5 commander, Colonel Stonehouse, has sour grapes about Mother being higher up the security services than he, so turns traitor in order to frame Mother for treason. He devises a secure breifcase and courier network which he contrives to lead to Mother's office, but it's all a bit too complex to actually work and his plans are lost in transit when the case is intercepted by the Avengers.
Devotee of the 'Gaslight Ghoul' and munitions trader Mark Travers plotted to destroy yet another world peace conference, thereby guaranteeing his profits, by killing off the delegates under the guise of the Victorian mass murderer, the 'Gaslight Ghoul' in this Holmesian telling of the Jack the Ripper case.
A confused plot about an international crime syndicate coercing a gormless military officer, in Charge of protecting the nation's treasures in the event of war so they can steal them is made more confused by later producers trying to salvage footage from a canned episode. Let's just move on, shall we?
Nigel Bromfield comes up with a plan to steal goverment secrets from top bureaucrat by causing them to fall in love with their char lady - actually one of his band, a young woman called Martha, and we're led on a riotous journey through the purple prose and sweet nothings of a Cartlandesque romance.