Jason King (TV series) the X-Men comics, the character of Jason Wyngarde (aka Mastermind) was partially inspired by Jason King and Peter Wyngarde. Mastermind had first appeared in the 1960s, but took on the appearance and identity of Jason Wyngarde in the build-up to the X-Men's first confrontation with the Hellfire Club in the late 1970s. Wyngarde had played the leader of another Hellfire club in "A Touch of Brimstone", an episode of the popular TV series "The Avengers", in which Diana Rigg appeared in a leather costume that Jean Grey adopted as the Hellfire Club's Black Queen. He is also one of the
A Town Called Mercy looking to give each episode of the series a distinct feel, showrunner Steven Moffat pitched the Wild West theme to writer Toby Whithouse, suggesting that the episode could be about a town terrorised by a robot. Moffat was keen on putting Matt Smith in a Western setting, who he called one of the last people one would expect to replace Clint Eastwood. Whithouse had previously written the "Doctor Who" episodes "School Reunion" (2006), "The Vampires of Venice" (2010), and "The God Complex" (2011). Moffat had been planning for the first five episodes of the series to have "movie marquee" themes.