The Keeper, played by Michael Rennie, is a zoo keeper. He wants to take the children and add them to his collection.

This episode is the only two parter from the series.

The second part of the zookeeper played by Michael Rennie. Rennie turns in a memorable performance as The Keeper. His understated performance keeps dramatic tension where none would probably exist with a lessor actor.

The Robinsons meet a space traveler who turns out to be an Earth man, Alonzo P. Tucker, who was abducted from Punxsutawney, Pennsylvania, by aliens, in 1876. Tucker befriends Will by telling tall tales about being a pirate, but it turns out that he is only an ordinary man being pursued by aliens because he has stolen a mind reading device from them. Tucker returns the mind reading device to his alien pursuers, saving the Robinsons in the process.

Dr. Smith holds a seance to contact his Uncle Thaddeus. Instead a spirit creature is contacted and creates havoc for the Robinsons. It is later discovered that the ""spirit creature"" is a physical creature, rendered invisible by the properties of the ""ionized gas"" in the bog from which it came.

Will and Dr. Smith stumble upon another robot. More capable than their own robot the alien robot works to gain the confidence of the Robinsons. At a critical point he plans to transport them to his home planet as slaves.

Penny and Judy stumble upon a mirror. They discover someone is on the otherside. Before they know it they are transported to the mirror universe which is occupied by only one person, a boy who is lonesome for companionship.

An alien boy is sent to Priplanis to validate his prince status. Will is drawn into a battle to the death unbeknowest to his father. Once his real intentions are known John substitutes himself in the challenge and the Alien Ruler substitutes himself for his son.

After the entire Robinson food supply is wiped out in a freak storm a trader arrives to trade food for equipment the Robinson's possess.

Dr. Smith trades the robot for food and hoards the supplies for himself. Later, after the Robinson's discover his transaction he gets the robot back but in exchange for his own self. The Trader then wants to take Smith as a slave, to another planet.

Dr. Smith is conscripted as the leader of a people from another world. Little does he know that the leaders of these people are routinely sacrificed and replaced with other expendible leaders. Smith is just one of a long line of sacrificed rulers.

The Beverly Hillbillies move to Priplanis. One of the aliens turns into a werewolf at night. The leader is a articulent female which Smith tries to court so he may have transportation back to earth. Don falls for the sexy alien daughter.

In this retelling of "The Midis Touch", Dr. Smith gains the power to turn anything into platinum. Penny is given a gift by a thief on the run, who tells her to protect it for him. She and Dr. Smith discover that it leads them to a ring which, when worn, allows the person to turn anything to platinum, which Dr. Smith does and enjoys. However, when it turns even his food to platinum, he is unable to remove the ring, which is now a solid bar. He leaves the camp as he fears turning everything into platinum, and he will eventually starve to death. A galactic lawman is on the trail, looking for the stolen device to use for his own nefarious purposes.

The Intergalactic Delivery Service comes to Priplanus. Once again Dr. Smith seeks transportation and has Will "test drive" the spaceship. Will returns much smarter than when he left. Smith realizing the same could happen to him, the increase of intellect, boards the spaceship. His trip, however, ends in his rapid aging and subsequent impending death. To make matters worse, the owner of the spaceship has returned to take the vehicle back, stranding Will and Dr. Smith in their altered state.

John Robinson is possessed by an alien spirit. The alien forces the family to prepare to return to the spirit's home world, even if it requires he sacrifice Will to keep his secret from the rest of the family.

Dr Smith and Will befriend an old miner named Nerim. After a series of earthquakes indicates that the planet is breaking up, Dr Smith tries to convince them that it is merely the effects of mining, and no harm will come to the planet. John informs him that he is wrong and that the Robinson family will be departing within the day. It is a race against time to escape the crumbling planet.

Shortly after leaving their original crash-site planet, Smith spots a familiar star and, in an amazing show of stellar navigational skill, calculates the course to get back to Earth.

He extracts a promise from Don and John that they'll return to Earth, or else he'll destroy his navigation data. They agree, but inform the family at dinnertime that they are headed for Alpha Centauri after all, mainly because the Earth is on the other side of the Sun (how do they know that? - do they know the date? And besides, from Alpha Centauri, Earth revolves clockwise, visible all the time). Smith changes course 180 degrees, then clumsily jettisons most of the fuel.

They reach a refueling barge, one of several that Alpha Control put out in 1996, top up the tanks, and resume course for Alpha Centauri, not knowing that they've picked up a tailgater who follows them after Smith reverses course to Earth again.

The alarm goes off in the night, and they expend a lot of fuel pulling away from the Earth's

Will and Dr Smith discover an old, abandoned Android Machine. When Dr Smith plays with the buttons on the machine, he accidently orders an Android. He thinks he has it for free, and uses her as his personal slave, assuming she has no human emotions. What will he do when the owner, Zumdish, and his guard turn up...demanding payment?

The Robinson's come across a group of space hippies who are trying to destroy the planet the Robinson's currently inhabit. Up up to the Robinson's and Dr. Smith to stop them or they will all be doomed.

The Jupiter 2 lands on a planet which serves as a junkyard. The Robinson's food supply is dwindling. So Dr. Smith tries to sell the robot and the ship in order to get food. Can Dr.Smith be stopped?