Season 3: The Time Merchant
Time travel stories are very difficult to tell. What happens in the past will influence the future. If you travel back in time, do you replace yourself or are there now two of you? In the case of this episode, the person traveling back in time replaces themselves temporarily until they return to their normal time. Then their old selves return to their normal place and time as if nothing happened. How convenient ... and stupid.
Dr. Smith, the robot and Will all travel back in time. For some reason, the robot's memory is somehow reset to what it was in the past but he managed to eventually remember who he really is. The Will that travels back in time is much older than the Will of 1997 before the Jupiter 2 lifted off into space.
When Will goes back in time, he conveniently appears next to the robot who has also gone back time instead of appearing where is younger self is. Stupid.
Will is also wearing his purple clothes from Season 3. When Dr. Smith went back in time, he was dressed in the clothes he wore at that time. Stupid.
Let's go back to the beginning. During a cosmic storm, Will creates a trap to capture cosmic particles but instead captures Dr. Chronos the Time Merchant. According to Chronos, he controls time. When they captured him, there was nobody running the factory so in his own words "The time tapes have gone amok. They're running backwards, sideways and upside down." He's lost time so he claims that Will owes him time so he hypnotizes Will and they return to his factory via the cosmic trap which as apparently opened up a dimensional opening. Prof. Robinson, the robot and Dr. Smith follow. There are no women in this episode. The stupid thing is that Prof. Robinson somehow knows how to travel through the dimensional portal by placing his hands just right. Stupid.
Dr. Smith seems to know how to use Dr. Chronos time machine. He jumps into the cage and throws the level and somehow he goes to the place and time he wants auto-magically. This happens over and over in this episode with Will, the robot and Prof. Robinson. Stupid.
Chronos explains "Everybody has a time tape. But if they run hither and tither, to and fro, back and forth, never slowing down for a moment ... they use their time tapes up all the faster." Chronos is a bad guy because he blows up planets that waste time so we're supposed to feel good when his factory gets blown up.
At one point, they need more power so Will gets on treadmill since they need axillary power. Stupid.
Dr. Smith travels back to 1997 right before the Jupiter 2 lift-off. He decides to stay on Earth of course. If Dr. Smith does not get on the Jupiter 2 then his weight will not throw off the trajectory and the Jupiter 2 will be destroyed by uncharted asteroids and the Robinson's will cease to exist. But now we'll have a time travel paradox. If the Robinson's die then Dr. Smith can never go back and time and avoid getting on the Jupiter 2 therefore he will get on the Jupiter 2 and we're stuck in an infinite loop. Dr. Smith and the robot get on the Jupiter 2 then are transported back to the future. At that point, the robot and Dr. Smith of the past must then continue the past time line.
At the end of the episode, the factory gets completely destroyed. Based on what Chronos said earlier, that should have destroyed time as well but apparently "time" is fine. Really stupid.
Bonus Stupid: Any SciFi show that goes around the universe finding humanoids that speak English can't be taken seriously. Lost in Space is one of those shows.