August 1967, and the third on 31 January 1969; BBC Enterprises retained the 16 mm films until 1977. A short extract from the first episode was used in the 1977 documentary Whose Doctor Who; an extended six-minute version of this sequence was kept by Jan Vincent-Rudzki, then-president of the Doctor Who Appreciation Society, who assisted with the documentary. At the Missing Believed Wiped event on 11 December 2011, it was announced that the third episode had been discovered earlier that year among materials owned by former television engineer Terry Burnett, who had purchased it at a school fete in the 1980s but not realised its significance until speaking to Ralph Montagu, head of heritage at Radio Times; the final shots and closing credits were missing from the episode, and the tapes featured some visual discrepancies that required cleaning. Critical response After the broadcast of the second episode, Bill Edmund of Television Today wrote that the characters were "a little sluggish after their holiday", praising Vicki and Steven's replacement of Ian and Barbara but describing the story as "rather slow". On Junior Points of View, presenter Muriel Young reported that some young viewers had called the programme "dreadfully boring" and "absolutely stupid". The BBC Programme Review Board after the third episode noted that television controller Huw Wheldon was satisfied with the Chumblies. The Listener noted that the end of the third episode—the Drahvins locking Steven in an airlock—was "nightmare food and could raise trouble among feminists as well as psychiatrists"; Monica Furlong of the Daily Mail recalled the ending after a similar scene occurs in "The Neptune Affair", a 1965 episode of The Man from U.N.C.L.E.. Retrospective reviews were positive. In The Discontinuity Guide (1995), Paul Cornell, Martin Day, and Keith Topping felt that the serial "presents an interesting if flawed twist on the traditional bug-eyed monster tale". In The Television Companion (1998), David J. Howe and Stephen James Walker described the story as "an unfailingly entertaining one", praising its original ideas and high production value. In A Critical History of Doctor Who (1999), John Kenneth Muir called the serial "intelligent", largely due to its unique philosophy of making the humanoids "monstrous" and the "ugly" characters friendly. In 2012, Radio Times reviewer Patrick Mulkern thought that the serial was "by no means a classic" but did have "sparks of originality", particularly in Lambert's changes to the Drahvins and Martinus's dramatic camera