Smith eats some alien fruit which transforms him into a giant. Convinced it was the Robinsons trying to kill him, he plots to take them out.

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.

The Robinson family banish Smith from the Jupiter 2.He takes refuge in an abandoned spaceship where he finds a machine that can materilise anything.In an attempt to get back into the Robinsons good books he gives them the machine which plays on the familys greed.

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.

Professor Robinson is caught in a matter transfer emission ray, and subsequently ends up in another dimension where he is confronted by a version of himself and Don. However this realm is the opposite of his own dimension, the anti-matter world, where everything in reality is twisted. The evil John returns to the family and attempts to take over the Robinsons and take over John's life. Will he get away with it, or are Will and the Robot able to defeat him, and restore the world to it's natural order.