'Lobster Quadrille' by Richard Lucas

After an agent is killed in a fire while investigating an increased level of radioactivity in seafood, Steed and Mrs. Gale arrive on the scene. They uncover a plot by Quentin Slim, a man thought to be dead, but who is alive and well and currently smuggling heroin. But Mrs. Gale is captured by Quentin, who plans to set fire to the hut where she is being held captive...

Patrick Macnee (John Steed), Honor Blackman (Cathy Gale), Leslie Sands (Captain Slim), Burt Kwouk (Mason), Gary Watson (Bush), Jennie Linden (Katie), Norman Scace (Doctor Stannage), Corin Redgrave (Quentin Slim), Valentino Musetti (Jackson)

Directed by Kim Mills
Produced by John Bryce

TX:
UK: 21st March, 1964

Notes:
*Featuring John Steed and Mrs. Cathy Gale

*This is Mrs. Gale’s farewell episode, as Honor Blackman leaves to appear in ‘Goldfinger’. The last scene was kept secret until it transmitted; there were a couple different possible endings, including one in which Mrs. Gale dies in the burning houseboat. The producers chose to keep it upbeat, and so Mrs. Gale bids Steed farewell as she leaves for a holiday. Steed buys her a bathing suit, and one of his last lines is a sly reference to her future role as Pussy Galore: “...pussyfooting along those sun-soaked shores...”