...Nor Iron Bars a Cage

Nor Iron Bars a Cage is the seventeenth episode of Ben 10: Ultimate Alien.

Plot
In the prison dimension Null Void, a prisoner called Trukk is released from solitary confinement and brought back to the mines. His cohort, Quince, tells Trukk that when Trukk was in solitary, a new prisoner came. That prisoner is revealed to be Kevin, who from the previous episode absorbed Ben's Ultimatrix and became a monster similar to his first mutation in order to stop Aggregor, becoming Ultimate Kevin.

Ben and Gwen got word that ever since Kevin left the team, he has gone on a revenge spree on everyone that wronged him. They visit a man named Barry at a hospital, who said Ultimate Kevin beat him up because he owed him money but forgot. Back in the Null Void, Trukk tries to get Ultimate Kevin's attention, only to be beaten up by Ultimate Kevin. Quince covers Ultimate Kevin by saying Trukk tripped on his pick-axe. Meanwhile, Ben and Gwen search Kevin's room. Ben sees the Null Void symbol scratched on the floor by Kevin, giving him and Gwen a clue to Kevin's whereabouts. During a lunch break, Quince finally recognizes Kevin, and apologizes to him for getting back in the prison. But Ultimate Kevin explains he went back in the prison for revenge against the warden, Morgg. Morgg and his robot guards find Ben and Gwen teleporting to the prison.

Ben and Gwen arrive to tell Morgg that Ultimate Kevin is going to kill him. Morgg ignores their warning, and has his robots take them to a room to stay in until a supply ship picks them up. Meanwhile, while the prisoners are still mining, Ultimate Kevin flashes back to the last time he was a prisoner. He was still mutated, and got so angry, he threatened to hurt all the prisoners. Quince, and his friend, Kwarrel, watched. Kwarrel walked up to Kevin, telling him to calm down. Kevin tried to fight Kwarrel, but Kwarrel easily defeated him, and told him to come to him to give up on the anger. Sure enough, Kevin did, and Kwarrel taught Kevin to calm down, to control his powers, and to absorb solids rather than energy. However, Kwarrel was being watched by Morgg, who by that time was a guard, and somehow started a riot between the other prisoners. Kwarrel and Kevin went down to a tunnel Kwarrel was digging up in order to escape, but Morgg found them, and while Kwarrel urged Kevin to escape, Morgg killed Kwarrel with his blaster. Back in the present time, Gwen is trying to open the locked door in her and Ben's room. Ben transforms into Goop, and frees them by burning the lock. Morgg and the guards catch Ben and Gwen in the mines, and he orders the guards to kill them. When they reach a dead end, Ben transforms into Humongousaur and destroys the guards, but inhales a blue dust that makes him see Gwen as a monster.

Ben fights Gwen, not knowing she is herself. Gwen finally snaps Ben out of the hallucination when she slaps him in the face. When Ben changes back, they realize Morgg is not only a prison warden, but an intergalactic drug trafficker. He is using the prisoners to mine an alien dream dust and sell it to the highest bidder. His plan where he replaced the old guards with robot guards is so no living guards can betray Morgg and reveal his plan to others. Ultimate Kevin and Quince confront Morgg, and Ultimate Kevin is about to kill Morgg to avenge Kwarrel's death. But Morgg activates the prisoners' collars, and they begin suffering an extremely painful shock, including Kevin and Trukk. When they notice the prisoners getting killed, Ben transforms into Echo Echo and uses his sonic abilities to destroy the collars. The prisoners destroy the rest of the robots, and Kevin was about to kill Morgg until Ben and Gwen arrive. As Ultimate Kevin was about to strike Morgg, Ben becomes Armodrillo and tries to prevent Ultimate Kevin from getting Morgg, but Ultimate Kevin is too strong and pushes Ben to the wall, where the mines collapse. Ben, Gwen, and Quince manage to escape, but Ultimate Kevin is trapped on the other side with Morgg. Ultimate Kevin chases Morgg and cuts the line to the elevator Morgg was using to escape. Luckily, Gwen is able to save Morgg, but he is arrested for his drug dealing. They notice most of the prisoners escaping, but Ben allows it, as they are still trapped in the Null Void. Ultimate Kevin also escaped, thinking Morgg is dead, and Quince stays as he still believes he has time to serve. Ben now believes Kevin is too dangerous, and tells Gwen they have to put him down, much to Gwen's horror.

Major Events

 * Reveals how Kevin learns how to use his powers properly.
 * Reveals how Kevin escaped the Null Void.

Characters

 * Kevin Levin (Flashback, main character of this episode)
 * Ben Tennyson
 * Gwen Tennyson
 * Berry
 * Quince
 * Kwarrel (flashback only)
 * Trukk

Villains

 * Ultimate Kevin (Insane)
 * Morgg

Aliens Used

 * Goop
 * Humungousaur
 * Echo Echo
 * Armodrillo

Errors

 * Kevin's shorts are miscolored blue in the flashback.
 * When Ben became Humungousaur, he yelled before he transformed.
 * In the scene where Armodrillo tackles Ultimate Kevin, Kevin's appearance is reversed, like looking at him in a mirror, see the picture on the right to see the error.
 * When Ben was in the Hospital, he had a white sleeve.
 * When Ben turns into Goop and goes outside the cell where he and Gwen are, the anti-gravity projector is also there, despite the door still being closed.

Allusions

 * The name of the episode likely comes from the poem by Richard Lovelace with a well known verse being "stone walls do not make a prison, nor iron bars a cage".
 * When the security drones say "uh oh", it could be refrencing the "Star Wars saga."

Trivia

 * During the flashback of when Kevin reverted his mutation, his appearance is not that of the original series but looks more like present day Kevin. Examples are from his hair and body.
 * During the week this episode premiered, Fusionfall released a Goop set.
 * Dwayne McDuffie revealed that after Goop lost his anti-gravity disk, the Ultimatrix would make a new one.
 * Somehow, when Goop went under the door, his anti-gravity projector got on the other side as well, despite it being made of metal.
 * This is the first episode that we see eleven-year-old Kevin from the original series, and we find out how he regained his sanity, human form, and gained his matter-absorbing powers and abilities.
 * The irony in the plot is Kevin trying to right a wrong for a friend, but sacrificed everything the friend stood for in doing so.
 * This episode where Kevin gets revenge on Morgg for Kwarrel's death is a resemblance to Vendetta, where Kevin gets revenge on Ragnarok for his father's death.
 * When Echo Echo used his sonic blast he yelled out Echo Echo.
 * Incarcecan was seen briefly in the "Ben 10: Alien Force" episode Vendetta when Ragnarok escaped from it.
 * The Null Void makes it's first appearance in Ultimate Alien.
 * In the flashback, Kevin's voice in his mutant form sounds exactly like his normal voice in Alien Force and in Ultimate Alien before mutating (again).
 * This is the second time Gwen has found a sock while looking for something. The first time was at the beginning of Voided.
 * This episode airs in the UK on the 22nd February 2011.
 * The Robot Guard's guns are the same as the DNAliens.