Ben 10 vs. the Negative 10: Part 1 is the fiftieth episode of Ben 10.
In a city, two thieves are flying away with a bag of jewels. Stinkfly flies up to them. They shoot him, but he dodges. They chase him around the city. Stinkfly covers their helicopter's windshield and stops their propeller with slime. They eject as the helicopter crashes into water. Stinkfly catches them and flies off and reverts back into Ben. The crooks are arrested and Ben, while on the roof top, wonders about if anyone can give him a challenge. On a nearby rooftop, a red robotic creature observes him.
In the morning, Max picks up his old Plumber friend's grandson, Cooper, from summer camp. In the Rust Bucket, Ben and Gwen are fighting over a radio contest, which causes them to lose. The prize was a ticket to the premiere of a movie and Cooper tells them that he has a ticket. At Fort Knox, three people in trench coats break away from their group. They remove their coats to reveal that they are the Circus Freaks and step aside to reveal Sublimino, who hypnotizes the guards. In the Rustbucket, Ben and Gwen are acting very nice to Cooper. Max calls Ben and Gwen to show them a video of the Circus Freaks entering the vault at Ft. Knox. Cooper asks what was with the video. Ben lies, but Cooper says that he knows all about the Omnitrix and the Plumbers (because of Max), and he demands a real explanation. The group goes to Ft. Knox. Ben offers to keep an eye on Cooper. Inside, they find guards acting like chickens and the vault melted open. Guards shoot at them and they run. Ben transforms into XLR8 and saves the chicken-guards. XLR8 then runs off, moves the guards out of the way, and confronts the guards that are shooting at him. He knocks them out, but more come. They aim a large gun and Max and Gwen.
An alarm goes off and an empty forklift knocks the guards over. Cooper was controlling it. The four go into the vault to find that all of the gold is still there. Cooper finds a passage melted open and XLR8 reverts back into Ben. Inside of the passage, there is an old Plumbers' base. Max can't figure out what the Freaks wanted. Elsewhere, the Freaks have a piece of technology that is stolen by the red robot. He gives it to Driscoll. Acid Breath clashes with Driscoll and rebels against him, but he is easily defeated by the Forever Ninja. In the Rustbucket, Cooper has made an autopilot. Max pulls up a map of old Plumber bases. An alarm is going off in Seattle. Cooper says that he made a turbo system. Max uses it to get to Seattle, but there are no brakes. Ben transforms into Diamondhead and climbs onto the roof. Diamondhead makes crystal roadblocks, but the Rustbucket smashes through. He makes a diamond anchor and throws it off. It manages to stop the Rustbucket, but tears up the street. Wasps come out from inside the building with the base and attack Diamondhead. They merge into Clancy and Diamondhead fights with Clancy, revealing that Clancy has transformed into an insect creature. Gwen casts a spell that sends the wasps towards Clancy and saves Cooper from him. In an elevator, Rojo attacks them and cuts the elevator. Diamondhead stops the elevator and carries them to their floor. There is a hole in the wall and Charmcaster and Rojo are there. Dr. Animo arrives and he has a bat with a sonic scream that knocks Diamondhead down. Diamondhead is surrounded by the three villains. Charmcaster defeats Gwen's magic skills. The Tennysons run off, leaving Cooper. Diamondhead fights Animo, Gwen fights Charmcaster, and Max fights Rojo. Clancy is there as well and attacks Max. Rojo grabs a component, which Max recognizes. He tells Ben and Gwen to stop Rojo. Diamondhead knocks Animo off of the building and tackles Rojo. Unfortunately, he reverts back into Ben. Ben grabs the component but he trips. Cooper catches it. Clancy corners him and he throws it off. Clancy flies after it, but Animo caught it. Rojo terrorizes Ben, but Clancy grabs her and Animo grabs Charmcaster and The villains fly off. In the Rustbucket, Max explains that the component the villains stole was one-half of the key to the sub-energy, a massive energy source given as a gift by an alien race. They arrive at Mt. Rushmore and are attacked by the whole group. Driscoll introduces them as the Negative 10 and sets them upon the Tennysons .
- This episode marks the 2-year celebration of Ben 10.
- Negative 10
Naming and Translations
|Hungarian||Ben 10 a Negatív 10 ellen, Első Rész||Ben 10 Against the Negative 10, Part 1|
|Portuguese (Br)||Ben 10 Contra os 10 Negativos: Parte 1||Ben 10 Against the Negative 10: Part 1|
|Spanish (HA)||Ben 10 Contra Los 10 Negativos: Parte 1||Ben 10 Against the Negative 10: Part 1|
|Spanish (Spain)||Ben 10 vs. Negativo 10 I||Ben 10 vs. Negative 10 I|
- In this episode the Forever King tells Acid Breath that he "Finds his lack of faith disturbing," a quote by Darth Vader in Star Wars.
- The Tennysons' and Cooper's forty-fifth, forty-sixth, and forty-seventh stops are Fort Knox, Washington, and Mount Rushmore, respectively.