The Diabolical Masterminds of Series 4 (1965–6)

British Intelligence is tipped off that a shadowy Eastern Bloc agent is arriving in London - the elusive Colonel Psev, as yet unidentified by our side, despite him being known to be behind many acts of espionage and sabotage across the Western world. He is preceded by his entourage Pudeshkin, Shvedloff, Elena and Vogel, who, it transpires are collectively the elusive Psev, their initials spelling the moniker. Steed is onto them, however, and fools them into tipping their hand by pretending to be his own doppelganger, by careful use of time-delayed television broadcasts and answering machines. Escaping their clutches with the wary Mrs. Peel - she still doesn’t believe Steed is himself, they manage to bring Psev low by turning a lethal model bomber upon its master(s).

Brandon Storey, eminent publisher and unassuming bon vivant, has discovered in Janice Crane a medium of extraordinary talent. a woman able to control the dreams of others (Sound familiar?) and steal government secrets from the most hard-nosed agents without the need for torture or physical contact. The process is not without its flaws, however, and their first target dies of a brain hemorrhage as a consequence, raising the suspicions of the Ministry.
Undaunted, they turn their attentions on Steed and induce him and Mrs. Peel down to Storey’s house for a not very merry Christmas.
Emma’s friend Jeremy Wade is spooked by the developments and tries to opt out, with fatal consequences, but the Avengers have already tumbled to the plot and thwart the villains by singing loudly (and badly) until they’re able to bring them to book after a shoot-out in a hall of mirrors.

Ormrod plans to hold the entire country to ransom, destroy the crops county after county until his somewhat paltry demand for £ 1,000,000 are met.
He’s got the technology from Clare, the daughter of disgraced scientist Dr. Prendergast, who thinks Ormrod intends to clear her father name. He developed a new fast-growing fertiliser powder which went horribly wrong, destroying miles of pristine arable land and killing off the wildlife.
Finding that flocks of birds are falling from the skies in a remote part of the West Country, the Avengers investigate, and uncover a degree of subterfuge and keenness for discharging shotguns around Ormrod’s estate.
He plans to split his ill-gotten gains with other prominent landholders; Croft, Mellors, Juggins and Snow, for whom £ 250,000 appears to be recompense enough for losing their livelihood - their farms will the first to be destroyed in the extortion scheme.
A rollicking ride later, and the villains are brought to hounds.

Max Chessman wants the largest hotel chain in the world, and nearly has it. However, he has his sights set on expanding behind the Iron Curtain, with resorts along the Black Sea coast and across to the Eastern oblasts - he might have set one up in Tannu Tuva! - but this will require the co-operation on the local authorities. We all know what that means.

He turns traitor, kidnapping leading British scientists and imprisoning them in cells on a secret level of his London hotel. The prisoners are made to believe they’ve been spirited away to North Korea by the broadcast of tapes recorded at a well-known prison camp; Steed himself was briefly incarcerated there. His managers and key personnel are in on the plot, as is a local Chinese laundry who help to make off with the scientists and smuggle them over the wall.

It all goes awry when one of the scientists escapes and makes it back to his house, but is now afraid of his Asian wife. The Avengers are quickly on the trail, especially after the laundry truck recaptures him, and the villains are quickly confined to quarters.

A bunch of bitter ex-Empire colonialists, repatriated to England after their adopted home declared its independence plan to return to Kalaya and take over, reclaiming what they consider to be their birthright.

Professor Swain, a zoologist who specialises in the tsetse fly has developed a new, more virulent strain of the insect and they plan to release it onto an uninoculated populace, bringing the country to a standstill while they march in and take over. Impervious to the flies by virtue of having had shots against it, they alone will be able to act.

They test it in secret in the English countryside, using the Kalayan Ex-servicemen’s club as a cover, but when one of their guinea pigs escapes, they have to shroud the operation in some pseudo-Voodoo mumbo jumbo. The Avengers don’t buy an inch of it, convinced that the victims are suffering from sleeping sickness. Emma and Steed are soon swatting the villains down, culminating in the release of the flies into the cold English spring, killing them in seconds.