Updated: April 06, 2022

"The Derelict" Alexander Singer Peter Packer, Shimon Wincelberg September 22, 1965

Maureen saves her husband and he makes the repairs to the ship, but an approaching comet heats the hull of the Jupiter-2 and the hatch door becomes stuck. Major West forces the door open and saves the couple. Next, the family finds a large alien ship which pulls the Jupiter 2 inside. The Professor and West explore the ship and try to figure out the craft's advanced navigation system in hopes of locating Earth. Meanwhile, young Will Robinson ventures onto the alien ship, followed by Dr. Smith. The two meet an alien creature and Will tries to communicate with it, but Smith hastily shoots with a laser gun. More aliens appear and the furious creatures chase everyone back to the Jupiter-2 which forces its way out of the alien ship to safety.

Guest stars: Dawson Palmer (Giant), Don Forbes (TV Commentator)