Fool's Gold

Fool's Gold is the thirtieth episode of Ben 10: Alien Force and the fourth episode of the third season.

Plot
Ben, Gwen and Kevin are assigned to Walton to find one of the aliens who came by Max. On the way to Walton, they stop to find a trail of poop made of solid gold. While travelling around the town they see that the locals are quite wealthy.

They meet Mayor Coleman and he explains that every 17 years the aliens come for the popcorn festival during their spring break. Gwen finds Orb and he was the one who called Max because his best friend Decka went missing.

Ben and Kevin watch the other aliens as they try to wreck a greenhouse. Ben transforms into Spidermonkey and stops them from tipping the house with his webbing. Another group throws a silo at him and Kevin, but they missed.

After all of them are tied up, the mayor asked them to release the aliens and reveals that the town's economy is based on the gold poop. Ben continues to search and Kevin follows him. After Kevin follow Ben Gwen meet Orb how is best friends with Decka and is worried.

When Ben and Kevin were keeping an eye on a large group of the alien, they end up having a battle with them. When Gwen and the Mayor show up and the mayor lets them go and tells the team that no matter what damage they have the town can use the gold poop to fix it.

After that Ben is going to look for Decka and Kevin follows him again and Gwen starts to think that Kevin is trying to avoid her. The mayor enters his barn to check on Decka, whom he kidnapped so that he'll have enough gold to pay off his debts. When Decka says he can't eat anymore, the mayor changed his diet to meat.

The festival is finally over and all the aliens went home except for Orb. Ben, Kevin and Gwen saw two empty spaceships, one is Orb's, the other is Decka's. Gwen tracks down Decka through his ship to the mayor's barn. The mayor attacks them with a laser gun. Ben, as Goop with Gwen and Kevin manage to defeat the mayor.

Decka then shows up in his feral form because eating the meat. Ben transforms into Big Chill and tries to freeze Decka, but failed to stop him. Orb warn them that Decka will eat anything and then split himself and the poop is now radioactive and unstable. Kevin accidentally steps on one and it sends him flying.

They find Decka at the power plant, absorbing energy. Big Chill freezes the reactor, making Decka eat the building instead. Orb tries to reason with him, but it also failed and tried to eat Orb. Ben then changes into Echo Echo because to his species, silicon is poisonous. Decka then eats all of the Echo Echo clones, causing him to vomit everything he ate and revert back to his original form.

Ben apologizes to Decka and promises that the mayor will be punished. Decka returns home with Orb angrily, saying that he will tell everyone to never return to Earth. Kevin gives Gwen a locket holding a picture of him before the mutation with her, asking her to remember how he used to be signifying he may have lost most of his hopes of returning back to normal.

Characters

 * Max Tennyson
 * Ben Tennyson
 * Gwen Tennyson
 * Kevin Levin
 * Orb (first appearance)
 * Decka (first appearance)

Villains

 * Mayor Coleman (first appearance)
 * Decka (feral form)

Aliens Used

 * Spidermonkey
 * Goop
 * Big Chill
 * Echo Echo

Allusions

 * Aliens remind gremlins, which should not be fed after midnight. Otherwise, they'll become monsters.

Trivia

 * The Brazilian Portuguese and Russian translations of this episode mistakenly say that Echo Echo is made of silicone instead of silicon.
 * The mayor citing weather balloons as an explanation for the aliens who have raised the car of Kevin is an explanation often used in movies.
 * Orb and Decka's Species visited Mars sometime in the past and turned it into the Red Planet when one or more members of their species accidentally ingested meat.
 * It was revealed in this episode that in the Ben 10 universe, Mars was called the Popcorn Planet before its destruction.