Bill Mumy wrote this script that concluded the series by returning the Jupiter 2 crew to Earth. After the cancellation of the show, He called Irwin Allen and told him about the script and that all the cast agreed to do. Allen told Mumy "don't send me the script, if you do I won't read it" and refused to go any further with it.
This was a table read with the original cast included on the Blu-Ray release of the series.