Written by Terry Nation and Dennis Spooner and directed by Douglas Camfield, the serial was broadcast on BBC1 in twelve weekly parts from 13 November 1965 to 29 January 1966.[b] In the serial, the First Doctor (William Hartnell) and his travelling companions Steven Taylor (Peter Purves) and Katarina (Adrienne Hill) become embroiled in the Daleks' scheme to design the ultimate weapon.The seventh episode's Christmas Day broadcast prompted the production team to write a self-contained comedic story, which ends with the Doctor addressing the audience.The Daleks' Master Plan received an average of 9.35 million viewers across the twelve episodes, an increase from the preceding serial but lower than the previous year.Retrospective reviews praised the direction, writing, and production design, but criticised the serial's length, incongruous seventh episode, and violent deaths of female companions.The serial's videotapes were wiped by the BBC in the late 1960s; three episodes were subsequently discovered and released on DVD, but the rest remain missing besides audio recordings.On the planet Kembel, the Doctor (William Hartnell) searches for medical aid for the wounded Steven Taylor (Peter Purves), who he leaves with the Trojan servant girl Katarina (Adrienne Hill).The BBC's director of television, Kenneth Adam, suggested the serial be expanded to thirteen episodes; head of drama Sydney Newman formally requested an expansion to twelve, to which producer Verity Lambert agreed if Nation and Spooner could share writing duties due to their work on The Baron.[10] Nation and Spooner met to discuss the storyline but mostly worked independently;[8] their outline varied in length, with two pages for the first episode, a paragraph for the tenth, and a brief sentence for the twelfth.[14] The seventh episode's broadcast on Christmas Day prompted the production team to write a self-contained comedic story, believing viewers would be uninterested in a complex narrative.Tosh was inspired to make the episode a parody of the police procedural series Z-Cars after one of its writers, Keith Dewhurst, turned down his request to write for Doctor Who.[4] The Doctor's address to the audience at the end of the seventh episode—in which he says "Incidentally, a happy Christmas to all of you at home"—was written in the camera script, though Tosh and Wiles claimed it was improvised by Hartnell.[24] Wiles and Tosh decided the serial should kill new companion Katarina for shock value, as writers of subsequent stories faced difficulty fitting her in, and they felt viewers may be unable to identify with her.[9] Spooner requested the reintroduction of the Monk from The Time Meddler (1965), which he had written;[18] he felt the character could provide humour and Butterworth's performance could alleviate Hartnell's work.[44] On 13 December, Hartnell announced he would retire from the role at the end of the season;[48] he backtracked the following day, stating he would be willing to stay for another two-and-a-half years, at which point he hoped the programme would be broadcast in colour.[67] The Stage and Television Today's Bill Edmunds criticised the seventh episode, particularly the Hollywood sequence, noting it "would have been much better with more chases, a few custard pies ... and less chat".[71][72] Paul Cornell, Martin Day, and Keith Topping of The Discontinuity Guide appreciated its "epic" ambition but felt its plot "was worthy of six episodes at most".[73] David J. Howe and Stephen James Walker lauded the direction, writing, and set designs, though felt the story occasionally meandered due to its length.[74] John Kenneth Muir considered the serial notable for its dark qualities and proving the Daleks' viciousness,[28] and Andrew Cartmel lauded Marsh's performance but found the story padded and Egyptian set unconvincing.[75] Radio Times's Mark Braxton appreciated the direction and set design and called Hartnell's performance "one of his best", but criticised the seventh episode's audience address and the eighth's cricket scenes.[83] Radio Times's Braxton called his make-up "strange" but wrote his "indeterminate nationality counters any cry of racism"; he otherwise praised the character as "one of the great villains" of Doctor Who and lauded Stoney's subtle performance.[92] Conversely, Valerie Estelle Frankel found Katarina's death the result of incomprehension rather than intention, describing her as "an exaggerated version of helpless companion".[89] Frankel similarly appreciated Sara Kingdom's individual strength but wrote "her top quality is that she accepts orders unquestioningly", which ultimately overshadows her abilities and results in her death.The second, fifth, and tenth episodes were included on the DVD set Lost in Time, released on 1 November 2004, featuring an audio commentary by Purves, Stoney, and Cusick.