had aired around the same time the previous year. The serial received an average of 8.35 million viewers across its four weeks. The Appreciation Index for the serial was considered low, dropping below 50 for the first and third episodes. The serial was sold extensively overseas in the late 1960s and early 1970s, including to Australia, Barbados, New Zealand, Sierra Leone, Singapore, and Zambia; it was no longer available for purchase from BBC Enterprises by 1974, and Australia returned its film prints in June 1975. The original 405-line tapes for the second, third, and fourth episodes were wiped on 17 August 1967, and the first was wiped on 31 January 1969. A complete audio recording of the serial survives, as well as some brief extracts recorded on 8 mm film from the Australian transmission. Critical response At the BBC Programme Review Board after the broadcast of the final episode, the general consensus (led by BBC1 controller Michael Peacock) was that it had been "too brutal"; Doctor Who co-creator, head of drama Sydney Newman, said that action had been taken, and head of light entertainment Tom Sloan felt that the finale was "far above the heads of child audiences". An Audience Research Report received mixed responses, with confusion that the storyline from "Mission to the Unknown" had not immediately continued; the performances and production was considered mediocre, though some welcomed the added humour and the historical setting. In Doctor Who: An Adventure in Space and Time (1982), Trevor Wayne described the characterisation as "generally weak and superficial", noting that Salter's performance as Odysseus was the strongest. Conversely, in Flight Through Eternity (1986), Mark Wyman praised most of the performances, particularly Ingham as Paris; he also applauded Searle's score for its innovation and sophistication. In The Discontinuity Guide (1995), Paul Cornell, Martin Day, and Keith Topping wrote that, despite effective performances, "the whole thing feels uneasy". In The Television Companion (1998), David J. Howe and Stephen James Walker praised Wood's sets and Vicki's "poignant and well written departure scene". In A Critical History of Doctor Who (1999), John Kenneth Muir noted that the serial "appears to have featured some of the same style and wit" as The Romans (1965). Mark Braxton of Radio Times (2009) similarly compared it favourably to The Romans, praising Vicki's departure and the performances of White, Ingham, Lemkow, and Salter. Paul Mount of Starburst (2021) lauded Cotton's "sophisticated"