by Terrance Dicks and Malcolm Hulke
Designed by Robert Macgowan
Directed by Kim Mills
A naïf Russian pianist, Stefan Veliko (Sandor Elès), giving his first concert in London, become embroiled in a plot to derail crucial East-West trade talks in London.
A stripper (Valerie Bell) is sent to his flat and is let in by Mrs Gale and Peterson (Bernard Brown), who are just going out. They leave her there to meet Stefan, and she pretends she's been assaulted by him and is murdered by her employer, Burns (Geoffrey Colville) for her trouble.
Veliko's security adviser, Zalenko (Nigel Stock) covers up the murder, assisted by Steed and Mrs Gale when they realise someone's attempting to blackmail Veliko to smear his nation. The East-West trade talks will be scuttled if the plan works, and the Avengers must stop them (sound familiar?). Steed and Zalenko settle in for a heavy drinking session.
Steed traces the girl to "Le Stud", a seedy strip club run by Burns and quizzes Darleen (Dorinda Stevens) over Polly's movements, but she knows nothing. Becoming concerned, she asks Burns, who dismisses her questions.
Steed returns to the club after hours, and is set upon by Burn's hired goons, and tied up.
Darleen overhears Burns and Peterson plotting a murder at the piano recital and decides she now has enough information for Cathy to get a reasonable price.
Steed escapes his bonds by burning the ropes on a gas heater. Heading back to Stefan's flat, he and Zalenko find him gone, listen to the recording of his 'phone calls and follow him to the club, interrupting an attempt to photograph him in a compromising position. Darleen then meets Cathy at the British Cultural Committee's office, offering information for £500 - they arrange to meet at the club, but when Cathy gets there, her contact is dead and she's captured by Burns, the killer of both girls. Steed rescues her in the nick of time and they head off to secure the recital.
Peterson intimidates Stefan, threatening to publish the photographs, and hands him a gun, ordering him to kill the Minister. Stefan refuses to go through with it at the last minute, and fights with Peterson. Steed and Zalenko apprehend Peterson and lead Stefan to safety, but Cathy spots a photographer (Leslie Glazer) fumbling with his gun and stops him using it.
The case closed, Zalenko joins Steed and Cathy for another mammoth vodka drinking session, during which he and Steed manage to drunkenly exchange hats.