Terrance Dicks worked together with Malcolm Hulke on scripts for "The Avengers" as well as other series before becoming assistant and later full script editor of "Doctor Who". Dicks worked on the entirety of the Jon Pertwee Third Doctor era of the program and returned as a writer scripting Tom Baker s first story as the Fourth Doctor: "Robot". His later scriptwriting credits on "Doctor Who" included the twentieth anniversary story "The Five Doctors". Dicks novelized many of the original "Doctor Who" stories for Target books and has written original "Doctor Who" novels for BBC Books.