With the Robinsons running out of food, Dr. Smith trades the ship and the Robot to a junk man for food.

Smith lands the pod on a planet where plants are the highest form of intelligence. The Robinsons land only to be captured by Tybo, a giant carrot. He plans to turn them into trees while Dr. Smith becomes a stalk of celery.

Doctor Smith disposes of a plant which has grown to an intense size, and becomes attached to the hull of the Jupiter 2.

Farnum B, the intergalactic showman, again encounters the Robinsons as he presents the Galaxy Beauty Pageant, and its sponsor wants Judy to enter - and win.

Don and Doctor Smith are sent to an intergalactic prison after coming across an escapee.

When the Robinsons nearly reach Alpha Centauri, they find a human base run by young people. They convince the adults that Penny and Will aren't their children and they leave in the Jupiter 2.

After making a deal with the Time Merchant, Dr. Smith returns to Earth just before the launch of the Jupiter II. If he doesn't get on it, the Jupiter II will crash into an asteroid.

Penny is kidnapped by aliens who think that she is the missing Princess Alpha.

Landing on a planet some shapeless beings duplicate the Robinsons and take the Jupiter 2 with the intent of conquering Earth. Will gets aboard to stop them.

John Robinson and Don West are transported onto a strange new world where their evil opposites exist and plan to change places with them. Will, the Robot and a reluctant Dr. Smith set out to find and help the real Don and John only to be pursued by an evil John Robinson.

Will meets a princess who is escaping two bounty hunters, yet Will gets kidnapped instead.

Two escaped thieves transform themselves into humans and pretend to be tourists as Smith turns the Jupiter 2 into a hotel.

Galaxic showman Farnum B. wants to exhibit the Robinsons in his zoo.

The Robot "falls in love" with an evil female robot sought by two aliens.

When a gaseous creature engulfs the Jupiter 2, the other crew members disappear leaving Will and Doctor Smith alone.

A group of space hippies is going to destroy the planet the Robinsons are on.

Accidentally landing on a planet, Will, Doctor Smith and the Robot find the Jupiter 2 is now an archaeological site and that they are in the future.

The Robinsons take a boy home to his planet and come across a spaceship that is a space lighthouse. The boy gets angry when they tell him they don't have enough fuel to get him home.

Using an alien machine Doctor Smith creates an army of cyborgs to conquer the universe.

On a planet where a primitive people are ruled by a computer, Doctor Smith goes against character and saves Major West's life.

After killing a hostile alien, Professor Robinson comes across a "hunter" and he must replace his dead prey.

A spaceship requests medical help for their computer and Dr. Smith has to perform brain surgery on it.

Passing through a time warp, the Robinsons do return to Earth in the year 1947. They are mistaken as invaders and start the UFO scare of the 194

The Robinsons leave their planet to escape a collision with a comet and find a ship full of frozen convicts.