sentences:  Written by William Emms and also known as "The Vampire Planet", not much is known about it.Written by Malcolm Hulke, not much is known about it, this six-part story was commissioned on 5 July 1968.The serial was cancelled on 30 December 1968 and its production budget allocated to "The War Games", which Hulke co-wrote with Terrance Dicks, allowing that story to be expanded to 10 episodes.