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.
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.
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.
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.
Lost in Space's only Christmas program. Will uses an alien transporter to send himself back to earth. However, many people believe the Robinson family to be dead after hearing the ship went off course. Nobody on Earth believes him, and they lock him up with the intention of sending him to a boys' home. Will escapes the family home he's in, and wanders around these clueless bunch of townspeople, but finds carbon tetrachoride — needed for the food processors on the Jupiter. Eventually he convinces another boy, Davey, to let him out, and let him return to the planet he came from. He returns to Priplanus with this bottle. Of course no one believes his adventures until he produces the bottle, plainly labeled as coming from Earth.
The women of Lost in Space are featured in their very own episode while the boys are out installing communications equipment. Smith is left in charge (boy is that a mistake) and he ""cleans"" their weapons, but cannot remember how to rebuild the weapons. This leaves the J2 crew defenseless. A creepy creature stalks the Robinson women however they think a small dog is to blame for raids on food and other mischief.
The Robinsons can not understand the language of a visiting family also on the planet. The aliens are called Taurons, and come to use the planet as a new colony. However Dr. Smith causes problems between the two camps when he panics and draws a gun on the new family. The Taurons end up not liking the planet and want to be alone, so they leave.
Professor Robinson discovers that the planets orbit will bring immense heat on the spaceship. With that knowledge the Robinson's take off in the chariot and head south. However back at the Jupiter two, Dr Smith who stayed behind because he believed them to be lying, realises that the orbit is strange, bringing immense cold followed by extreme heat. He sends the Robot to tell them, and they then attempt to travel back to the Jupiter 2. However in their way is a huge in-land sea which previously had been frozen solid. The immense heat and cold make the vegetation charred. They survive the heat and return to the Jupiter Two where they are most safe.
Professor Robinson attempts to explore a planet that the Robinson's are planning to land on. His para-jet propulsion system fails due to sabotage by Dr. Smith. Major West "lands" the Jupiter II, in spite of the fact that Dr. Smith has also sabotaged the propulsion system of the Jupiter II, and the family and Major West rescue Professor Robinson.
In the year 1997 the Robinson family take off to colonize Alpha Centauri. A spy from a foreign country AKA Dr. Smith becomes trapped aboard trying to sabotage the project. The ship is whisked off course and into a meteor storm due to Dr. Smith's extra weight upsetting the navigational computers. Smith desperately tries to save himself by reviving the crew. The result: the Robinson family becomes lost in space.