sentences:  The original script was sent back for rewrites, and due to a pay dispute the rewrites were not made until after Susan had left the series; this necessitated further rewriting.A third submission was similarly rejected as Ian and Barbara were due to leave, and the script was dropped.The story was the subject of an April Fool's Day prank in 1983, when "Doctor Who Magazine" issue 76 claimed that one episode had in fact been filmed and rediscovered, and would be integrated into a twentieth anniversary special co-starring the Fifth Doctor entitled "The Phoenix Rises".