The interrogators: Agents are called in for crash courses in interrogation - but their contacts keep disappearing. Teleplay writers, Richard Harris, Brian Clemens ; director, Charles Crichton ; director of photography, Peter Jessop ; editor, Karen Heward ; costume designer, Alun Hughe The Rotters: A murder spree hits the timber industry and its up to Steed and Tara to nail down the unlikely villains. Teleplay writer, Dave Freeman ; director, Robert Fuest ; director of photography, Alan Hume ; editor, Manuel del Campo ; costume designer, Alun Hughe Invasion of the Earthmen: After the death of a fellow agent, Steed and Tara uncover a plot to conquer space and come face to face with their worst fears. Teleplay writer, Terry Nation ; director, Don Sharp ; director of photography, Gilbert Taylor ; editor, Lionel Selwyn ; costume designers, Pierre Cardin, Harvey Goul Killers: Dead agents are piling up in a graveyard so Steed works with Lady Diana Forbes Blakeney to expose the secret at the heart of the murder spree. Teleplay writer, Tony Williamson ; director, Cliff Owen ; director of photography, Peter Jessop ; editor, Ann Chegwidden ; costume designer, Alun Hughe The morning after: When Steed and a traitorous agent wake up to a plot to detonate a nuclear bomb, the former enemies work together to prevent a catastrophe. Teleplay writers, Richard Harris, Brian Clemens ; director, John Hough ; director of photography, H.A.R. Thomson ; editor, Manuel del Campo ; costume designer, Alun Hughe The curious case of the countless clues: Pursuing a band of callous criminals, Steed suddenly finds the tables turned when the killers target Tara. Teleplay writer, Philip Levene ; director, Don Sharp ; director of photography, Gilbert Taylor ; editor, Lionel Selwyn ; costume designers, Pierre Cardin, Harvey Goul