Prisoner Number 775 Is Missing

Prisoner Number 775 is Missing is the 32nd episode of Ben 10: Ultimate Alien and the second season finale.

Plot
This episode starts with Old George walking towards Area 51 and approaching two guards. While the guards try to politely get rid of him, Old George, with surprising strength, knocks them out and goes inside Area 51, where a bright light shines, making the base disappear. Meanwhile, Swampfire, Gwen and Kevin are roasting hot dogs, when Grandpa Max gets a call from Cooper about Area 51's disappearance. They decide to go to Area 51 to investigate what happened. Max, Ben, Gwen and Kevin arrive at Area 51 and meet with Cooper and Colonel Rozum, according to Cooper there are no signs that the base was destroyed or teleported away, it just up and disappeared. They go down to the crater where the base was and find a level 3 tech floor, where Colonel Rozum reluctantly explains it is part of a holding facility for alien combatants that has been held up to the past 50 years and Ben turns into Big Chill to investigate under what is there while Max and Rozum argue over the conditions and finds a bunch of trapped aliens in cells and that there are exactly 774 aliens. But Colonel Rozum says that there is supposed to be 775, where an invisible lizard like-alien boards Cooper's Plumber ship and attempts to escape with it. Ben transforms into Rath and uses his long black claws to cling himself onto it to catch the escaped prisoner, but eventually falls off and seemingly, down to his unexpected death.

However, Ben was able to survive and find the damaged Plumber ship landing on a dock. They find the ship empty but by crashing and abandoning it the prisoner accidentally set it to self-destruct and Kevin tried to deactivate it, but sped it up.

Ben transforms into Echo Echo and produces an army of clones that throws the ship into the lake, but the lake was too shallow and the ship blows up. They find a town where the alien is attacking. Ben transforms into Humungousaur and he and the group fights Prisoner 775.

After Gwen traps him in a mana sphere, he says that 50 years ago he was a soldier fighting a dictator on his world before being exiled to earth and captured by the American airforce and in his absence his family was killed. Kevin suggests him to "even the score" and Ben advising him to seek justice, which ultimately leads him to decide to exact revenge on Colonel Rozum and his family for his imprisonment and tricks Gwen into letting him free, where the building crumbles around them, but are protected by Gwen's shield. They decide they must stop Prisoner 775 from killing Colonel Rozum and his family.

The group informs Max and Cooper of Prisoner 775's revenge plan and fly to Florida to find Colonel Rozum before he does. However, it is revealed Prisoner 775 hitched on the ride and runs away. Ben transforms into Wildmutt to track him. 775 finds Rozum's house and suggests whether not to attack when he sees his wife and a child, but suddenly is attacked by Ben and the group.

When he seems too stealthy to take on and when he was about to kill Rozum, Ben transforms into Ultimate Wildmutt and stops him, but 775 begs for Ben to kill him so he can be reunited with his family and cries over their deaths, shocking Rozum.

Spared, 775 is then taken by the Plumbers while Ben scans his DNA and unlocks its transformation. Ben transforms into ChamAlien and while Gwen and Kevin walk away with Ben following them, with the mess resolved Max takes the opportunity to chew out Rozum, he can use whatever justification helps him sleep at night, but the simple fact remains if he had shown simple mercy to 775 and followed proper procedure all those years ago he would have prevented the destruction wrought today and the reckless endangerment of Rozum's family and the lives of others.

Major Events

 * The Merlinisapien DNA sample for ChamAlien is unlocked by scanning Prisoner 775.
 * ChamAlien makes his debut.
 * Area 51 is introduced and shown to be an alien prison which is illegal under interstellar law.
 * Old George returns.

Ultimatrix Alien Debuts

 * ChamAlien (unlocked by scanning Prisoner 775)
 * Ultimate Wildmutt

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Kevin Levin
 * Max Tennyson
 * Cooper Daniels
 * Colonel Rozum
 * Rozum Family

Villains

 * Prisoner 775 (main villain of the episode)
 * Old George
 * Colonel Rozum

Aliens Used

 * Swampfire
 * Big Chill
 * Rath (accidental transformation ;selected alien was Humungousaur)
 * Echo Echo (accidental transformation; intended alien was Humungousaur)
 * Humungousaur
 * Wildmutt
 * Ultimate Wildmutt (first appearance)
 * ChamAlien (first appearance)

Errors

 * While Echo Echo was running away from the exploding Plumber Ship, his contour has a covered part of the Ultimatrix.
 * Right after the above error, the Ultimatrix symbol disappears.
 * When Ben's team was picking up the sheriff who was knocked out, his badge changed from gold to blue.
 * In one scene, after Humungousaur fought Prisoner 775, Prisoner 775's spout on his body appearance is reversed.
 * When Prisoner 775 slipped from Gwen's mana-shield, his teeth contours were the same colour as his skin.
 * When Gwen was shielding the prisoner, Kevin was shifting between his normal form and his metal form. This error is like the error of the episode Ben 10,000 Returns when he was shifting between his normal and his metal form.
 * When Prisoner 775 looked at the window of Colonel Rozum's house, it showed Rozum's wife holding their baby who had only a white blanket over him. But in the next scene, the baby was chewing a blue pacifier in his mouth.
 * After Prisoner 775 looked at the window and Wildmutt jumped on him, he threw Wildmutt back, saying Leave me be, I intend to balance the scales, his eyes were reverse colored, but then changed back to the regular colors.
 * When Ultimate Wildmutt was holding Prisoner 775's tail, his upper lip wasn't black.
 * The amount of strength that Prisoner 775 has rapidly changes throughout the episode.
 * When the Ultimatrix was stating that prisoner 775 was available, it was colored darker.

Allusions

 * The name of the episode could be a homage to the Doctor Who episode 'The Eleventh Hour' specifically the quote 'Prisoner Zero has escaped'.

Trivia

 * This is Max's last chronological episode of Ultimate Alien due to the fact that his next one would be a stock footage flashback.
 * It is revealed that Earth is in direct violation of interstellar law.
 * Ben reveals he shouts out his alien's names to strike fear into his enemies.