Prisoner Number 775 Is Missing is the thirty-second episode of Ben 10: Ultimate Alien.
This episode starts with 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 (after he transforms back into normal) , Gwen, and Kevin arrive at Area 51 and meet with Cooper and Colonel Rozum, and according to Cooper, there are no signs that the base was destroyed or teleported away, it just 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. Ben transforms 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, with 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 transformed 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, Rath was able to survive and find the damaged Plumber ship landing on a dock and transforms back into Ben. 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 transformed 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. Echo Echo transformed 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 homeworld before being exiled to Earth and was captured by the American airforce. in his absence, his family was killed. While Kevin suggests him to "even the score", and Ben advises him to seek justice, this ultimately leads him to decide to exact revenge on Colonel Rozum and his family for his imprisonment. He 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 transformed into Wildmutt to track him. 775 finds Rozum's house and suggests whether or not to attack when he sees his wife and a child, but is suddenly attacked by Wildmutt and the group.
When 775 seems too stealthy to take on and when was about to kill Rozum, Wildmutt transformed into Ultimate Wildmutt and stops him, but 775 begs for Ultimate Wildcat to kill him so he can be reunited with his family and cries over their deaths, shocking Rozum.
Spared, Prisoner 775 is then taken by the Plumbers while Ultimate Wildmutt transforms back into Wildwutt, and then Ben and scans his DNA and unlocks its transformation. Ben transforms into ChamAlien, while Gwen and Kevin walk away with ChamAlien 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.
- ChamAlien is unlocked by scanning Prisoner 775.
- ChamAlien and Ultimate Wildmutt make their debuts.
- Old George returns.
Ultimatrix Alien Debuts
- Area 51 is introduced and shown to be an alien prison, which is illegal under interstellar law.
- Ben reveals why he shouts the names of his aliens whenever he transforms.
- Ben Tennyson
- Gwen Tennyson
- Kevin Levin
- Max Tennyson
- Cooper Daniels
- Colonel Rozum
- Rozum Family (first appearance)
- Big Chill
- Rath (selected alien was Humungousaur)
- Echo Echo (intended alien was Humungousaur)
- Ultimate Wildmutt (first appearance)
- ChamAlien (first appearance)
Naming and Translations
|Hungarian||A 775-ös rab eltűnt||The Prisoner Number 775 Is Missing|
|Portuguese (Br)||O Prisioneiro Número 775 Sumiu||The Prisoner Number 775 Disappeared|
|Spanish (HA)||El Prisionero 775 No Está||The Prisoner 775 Is Not Here|
|Spanish (Spain)||El Prisionero 775 Se Ha Escapado||The Prisoner 775 Has Escaped|
- Ben reveals he shouts out his aliens' names to strike fear into his enemies.