Dr. Smith, Will, and the Robot are at the doctor's winemaking apparatus a short distance from the Robinson campsite when a hairy, grunting creature suddenly appears carrying a sophisticated electronic mechanism. The monster follows them back to the campsite where it sets the box down just outside the camp perimeter. The box reveals itself as a combination of communications device and jailer, as it announces the Robinsons are under investigation by the Galactic Tribunal of Justice for alleged crimes committed in space. The camp is then surrounded by an energized fence that traps everyone inside of it.
Prof. Robinson is the first to be called before the tribunal where he learns of how his actions in "The Derelict" have affected the bubble creatures that were inside the ship. Major West testifies next where he is accused of leaving a contaminated wrench floating in space. As each is testifying, Dr. Smith wonders why he hasn't been called, knowing full well that he is most likely the true cause of all of the crimes of which the others have been accused. After WIll testifies, the aliens decide to call Dr. Smith to the stand, causing Smith to panic. With help from Will and the Robot he escapes to his winemaking lab. The alien judge threatens everyone with imprisonment when Smith is found to have escaped, but Will convinces the judge to let him go and get Dr. Smith. The Robot goes along as well to help Will, which is useful as WIll cannot convince Dr. Smith to return but the Robot manages to do so under threat of dragging Smith back to camp forcibly.
In the courtroom Smith lies and panics, unknowingly insulting the judge by referring to the Bubble Creatures (the judge is one) in disparaging terms. He is returned to the Robinson camp where Prof. Robinson has drafted a petition to the court stating that Smith is mentally disturbed and thus cannot be held accountable for his actions. Although Smith raves that "I'd rather go to prison for a hundred years!" he relents after Major West suggests the tortures that the aliens might be capable of. The court accepts the petition under the condition that Smith have a court-appointed guardian to keep him out of trouble. They give this role to the Robot, who tells Smith that he must now "get up early, work hard, and speak only when spoken to." The episode ends with Smith pleading to the aliens to take him to jail rather than let this be his fate.
- Footage is shown from previous episodes.
- Why a civilization that has mastered matter transmission needs to have a grunting monster deliver its communications device is never explained. Perhaps it is to scare the Robinsons all into their campsite before setting up the force field fence.
- The cardboard tubes used to make the energy fence posts clearly show their seams on close-up but the plastic wrap used to make the fence itself holds up well during filming.
- Smith's wine-making lab contains old-fashioned wooden barrels and apparently no grapes..
- When the Robot tells Dr. Smith that because the Memory Machine will reveal the truth his fate is sealed, Smith replies "And the voice of doom is heard in the land!" This is a paraphrase from a verse in the Song of Solomon in the Bible -"And the voice of the turtle [dove] is heard in the land"
- Among the aliens in the courtroom is a Bubble Creature from The Derelict, the enormous bug from the final scene in The Keeper: Part 2, and the large flies who appear later in The Galaxy Gift.
- After the electrical fence surrounds the ship, John says, “An electric fence around the campsite could be dangerous. We’d better be careful not to touch it.”
- In the episode “Return From Outer Space” it is stated that eggs are rare commodities which the Robinsons do not have. In this episode, they are clearly eating eggs for breakfast. Where could they have come from? Although they might be able to grow vegetables, it is very unlikely the Robinsons can grow chickens... Although, it is possible that being on a different planet may have had something to do with it!
- Though all the Robinsons (and Don) are named in the original conviction, only the males are actually called to testify before the Galactic Tribunal, while the females are ignored. Apparently the Galactic Tribunal of Justice is a tad sexist.
- While working at the still, Robot waves his hooks in the air and screams “Warning, alien presence!” Smith scoffs at him and ignores the warning. Will brings up the exact thought I had myself at the time, which is that the Robot is never wrong about such things. Why would Dr. Smith ignore him?
- Dr. Smith hurls insult after in this episode. Some are: Ridiculous Roustabout, Cackling Clod, Disreputable Dunderhead, Mental Midget, Cowardly Clump, Pathetic Pompsity, Inept Idiot, Lugubrious Lump, Parsimonious Puppet, Bubble-Headed Booby, Tyrannical Tin Plate