Johnny Byrne (27 November 1935-2 April 2008) wrote the Doctor Who television stories The Keeper of Traken, Arc of Infinity and Warriors of the Deep and the unmade The Guardians of Prophecy which was produced on audio by Big Finish as one of The Lost Stories. He wrote two scripts for Doctor Who movies: The Time Lord in 1988, a re-write of a screenplay by Mark Ezra, and Last of the Time Lords in 1991. Neither movie was produced. (REF: The Nth Doctor) Before his involvement with Doctor Who, he was well known for his work as a writer for Space: 1999.
As Nyssa was only ever intended to appear in The Keeper of Traken, Byrne enjoyed the rights to that character and thus received royalties whenever she was used.
- Internet Movie Database at the