...Nor Iron Bars a Cage

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

Plot
In the pocket 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 he 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 Ultimate Kevin left the team, he has gone on a revenge spree on everyone who did him wrong. They visit a man named Barry at a hospital, who said Ultimate Kevin beat him up because he owed him money ($5) but forgot. Back in the Null Void, Trukk gets Ultimate Kevin's attention, only to almost be defeated by Ultimate Kevin. Quince covers Ultimate Kevin by saying Trukk tripped on his pickaxe. 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 Ultimate Kevin's whereabouts. During a lunch break, Quince finally recognizes Ultimate Kevin and apologizes to him for getting back in the prison. Ultimate Kevin explains that he returned to the prison for revenge against the warden, Morgg. Morgg and his robot guards then 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 Kevin 11 and got so angry, that he threatened to hurt all the prisoners. Quince and his friend, Kwarrel, watched. Kwarrel walked up to Kevin 11, telling him to calm down. Kevin 11 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 11 did and Kwarrel taught Kevin 11 to calm down, to control his powers, revert to human and to absorb matter 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 for years in order to escape, but Morgg found them. 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 destroy them. When they reach a dead-end, Ben transforms into Humungousaur and destroys the guards, but inhales a blue dust that makes him see Gwen as a monster.

Humungousaur attacks Gwen, not knowing that she is herself. Gwen finally snaps Humungousaur out of the hallucination when she slaps him in the face. When Humungousaur 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. But Morgg activates the prisoner's collars by which they begin suffering an extremely painful shock, including Kevin and Quince. When they notice the prisoners being killed, Ben transforms into Echo Echo and uses his sonic abilities to destroy the collars. The prisoners destroy the rest of the robots and Ultimate 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 Armodrillo 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 anyway. Ultimate Kevin also escaped, thinking Morgg is dead and Quince stays, as he believes he still has time to serve. Ben now believes Kevin is too dangerous and tells Gwen that they may have to put him down, much to Gwen's horror.

Major Events

 * Kevin's past is revealed (how he learnt how to use his powers and escape the Null Void).

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Barry
 * Quince
 * Kwarrel (flashback only)
 * Trukk

Villains

 * Ultimate Kevin
 * Morgg

Aliens Used

 * Goop
 * Humungousaur
 * Echo Echo
 * Armodrillo

Errors

 * In the scene where Armodrillo tackles Ultimate Kevin, Ultimate Kevin's appearance is reversed.
 * In the hospital, Ben had a white sleeve.
 * When Kevin 11 reverted to his human form, his shorts were blue instead of brown.
 * When Goop goes under the door of the room he and Gwen were locked in, it is unknown how his anti-gravity device got to the other side

Allusions

 * The name of the episode comes from the poem by Richard Lovelace with a well-known verse being "stone walls do not a prison make, nor iron bars a cage".
 * When the security drone says "uh oh", it is a reference to the Battle Droids from the "Star Wars saga."

Trivia

 * During the week this episode premiered, Fusionfall released a Goop set.
 * Dwayne McDuffie revealed that after Goop lost his anti-gravity disk, the Ultimatrix made a new one.
 * The Null Void makes its first appearance in Ultimate Alien.
 * The Robot Guards' guns are the same as the DNAliens', only blue.
 * Greg Cipes replaces Charlie Schlatter as the voice of young Kevin.