The Tenth Planet of malevolent cyborgs that became a recurring adversary in later "Doctor Who" stories. The "tenth planet" in the title makes reference to a fictional lost planet in Earth's Solar System; at the time of production, the Solar System was generally held to consist of nine planets, prior to the redesignation of Pluto as a minor planet. "The Tenth Planet" is an incomplete "Doctor Who" serial – one of many serials that were affected by the BBC's policy of wiping archived programmes in the 1960s and 70s. Only three of the four episodes are currently held in the BBC archives; the
Gustav Holst of the work was given at The Old Vic, preceded by an introductory talk by Vaughan Williams. "The Times" praised Holst and his forces for "a most interesting and artistic performance of this very important work". After this success, Holst was disappointed the following year by the lukewarm reception of his choral work "The Cloud Messenger". He again went travelling, accepting an invitation from H. Balfour Gardiner to join him and the brothers Clifford and Arnold Bax in Spain. During this holiday Clifford Bax introduced Holst to astrology, an interest that later inspired his suite "The Planets". Holst cast his