Grounded

Grounded is the twentieth episode of Ben 10: Alien Force.

Plot
While fighting one of the Highbreed, Ben's parents catch him transforming into Swampfire. They forbid him from using the Omnitrix after having proof of a black eye from the fight, forcing Kevin and Gwen to fight the DNAliens by themselves. After trying to sneak out as Echo Echo, Ben gets grounded and is made to spill the beans about Gwen, getting her grounded, leaving Kevin alone. Kevin's trouble with the DNAliens and the Highbreed eventually pushes Ben over the edge, and he breaks out of his house as Humungousaur in front of his parents to help. After a short battle aboard a small freighter carrying a rare isotope which the DNAliens plan on using, Ben's parents come to the rescue, admitting that they are proud of Ben and understand what he needs to do.

Major events

 * Ben's parents learn about Ben's life of fighting evil villains with the Omnitrix, and Grandpa Max being a Plumber.

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Kevin Levin
 * Carl Tennyson
 * Sandra Tennyson

Villains

 * Highbreed
 * DNAliens

Aliens Used

 * Swampfire
 * Echo Echo
 * Humungousaur

Errors

 * When Kevin is facing the Highbreed for the second time, some of the black patterns are missing from the Highbreed's shoulders. Later when Kevin is captured and confronting with the Highbreed before Ben's entrance as Humungousaur, the missing patterns are back in place.

Trivia

 * It is unknown how Ben (as Humongousaur) was able to run all the way to the docks, swim to the ship, and from there beat the Highbreed all in ten minutes.
 * Even though it's shown that Ben and Kevin have still some rivalry going on, it's also shown that they both care equally about each other.
 * This is the official episode that Ben's parents find out about him being a Plumber. There was a lost episode that Ben's parents found out in the original series, but it involved Vilgax and it was non-canon.
 * It appears that the Omnitrix aliens used in Ben 10 Returns: Part 1 have been repeated in this episode in the same order.
 * This is the episode where Ben answers his cell phone as an alien for the first time.
 * Sandra says about "MyFacing", possibly a reference to MySpace and Facebook. But, giving Ben's confused reaction, she might have mixed up the names.
 * The third hint towards the events of War of the Worlds is foreshadowed between the talk of Ben, Kevin and the Highbreed.
 * Gwen says about "Wifipedia" referring to Wifi and Wikipedia because they might have mixed up.
 * When Ben is explaining about the Omnitrix to his parents, he says the DNAliens are the ones who are planning to destroy Earth, but it is actually the Highbreed who want to destroy Earth, the DNAliens merely serve them. However, Ben could've just put them under the same group to make it easier on his parents.
 * Ben and Gwen have the same screensaver on their computers in the episode.
 * Although it is mentioned in Good Copy, Bad Copy that Ben's left eye twitches when he lies, it does not twitch when he lies to his parents about fighting the Highbreed.