Duped is the second episode of Ben 10: Ultimate Alien, the second episode of the first season and the 100th episode overall.
The Forever Knights try to invade the museum using an alien paramilitary tank, but they're interrupted by Ben as Rath. Gwen calls Rath and tells him that he's missing Julie's tennis game. Rath sees the Forever Knights running away, gets angry, and tears apart their tank, then heads to the stadium for Julie's game. When Julie is about to begin her match, Ben shows up and makes a huge hit of himself, blowing her concentration in the process. Julie and Gwen get mad at Ben for showing up late. Kevin wants to investigate why the Forever Knights tried to rob the museum, but Gwen disagrees on going, stating that they're probably stealing some tech to rule the Earth. Ben also wants to catch the Sumo Slammers movie, but Gwen tells him not to. She tells Ben he can't be in two places at once.
Ben then comes up with a plan and transforms into Echo Echo and splits into three, then turns back and this time there are "three Bens". One of them is the "logical" Ben, the second is the "sensitive" Ben, and the third is the "arrogant" Ben. However, he doesn't know this. The logical Ben goes to the Sumo Slammers 3-D movie, the sensitive Ben goes with Kevin to investigate the Forever Knights robbery, and the immature Ben stays to watch Julie's match. The Forever Knights, meanwhile, and their king Urian find a shortcut to the museum to claim ultimate power.
Unfortunately, immature Ben keeps embarrassing Julie, much to the annoyance of her and Gwen, sensitive Ben keeps annoying Kevin by blabbing about feelings, personal issues, and tight subjects. Kevin then has it when he was talking how Gwen and him are together and Ben telling him since that his cousin and says that they might become a family. Eventually Kevin says, "BEN, you've always been kinda girly, but today, you're CREEPING ME OUT!!!!" but the logical Ben is having a good time at the movies or at least so far.
Kevin and sensitive Ben fall into the basement of the museum and meet Urian and his Forever Knights. Urian makes his minions fight sensitive Ben and Kevin, where he's still annoying Kevin due to his personality, e.g. he says to Urian,"Excuse me, sir, but the signs clearly say do not touch the exhibits (holding up the sign)". They knock Urian's minions out and find out that he's after an Toltech Battle Armor, which he uses to attempt kill sensitive Ben and Kevin. This is sensitive Ben's fault, because he stalled Kevin, saying that enemies were people, too, while Urian assembles the Aztec alien battle armor. The sensitive Ben calls logical and immature Ben for backup. The two Bens hurry to the museum to help sensitive Ben and Kevin. When Kevin sees all three Bens, he responds with," If I wasn't running for my life, I'd demand an explanation!" Sensitive Ben and logical Ben try to explain, but at the end, immature Ben cuts them off by saying, to Kevin "What's it to you?" and Kevin repeats that he's running for his life.
Then, all three Bens change into Big Chill, Murk Upchuck, and Cannonbolt to fight Urian, but fail due to their weaknesses, differences, and their confusion (Cannonbolt slips on Murk Upchuck's slime while Murk Upchuck gets frozen by Big Chill). So all the Bens change into Echo Echo, and go back into one Ben. Ben uses Lodestar to finally stop Urian. Even though Julie won the tournament, she was upset at Ben thanks to his arrogant clone embarrassing her. She kindly asks Ben to make it up for her by taking her to see the Sumo Slammers 3-D movie, but Ben tells her that he saw it during her match, which causes Julie to be very furious. She and Gwen storm off in disgust along with Kevin, leaving Ben all alone to repent for what he has done in order to gain back their trust.
Ben: I'm glad you won your tournament, Julie. Julie:(sarcastically) Yeah, thanks. Gwen: You should have been there, and by that I mean you should have been there. Ben: Ok, Gwen. (scowls) Julie: Ben, I know you were off fighting bad guys. I was upset. But, I guess that's a deal when you decide to
date a superhero. Ben:(trying to please and calm down Julie) Julie, I promise, I'll make it up to you. Whatever you want to do, I'm there, just name it. Julie:(calmed and pleased, ready to give Ben another chance) Well, maybe we can go see Sumo Slammers: The Movie together. Ben: Actually, I, uh... already saw it. Julie: When...? Ben: Uh... during your match..? Julie: Well, that's just... oh! (furiously storms off) Gwen: Nice. (storms off after Julie) Kevin: Man, you are so insensitive. (walks out too, leaving Ben alone in the stadium to repent on what he did)
Humungousaur:(Starts to follow Kevin and hits his head on a pole) (transforms back into Ben) Sensitive Ben:(rubbing his head) Ow!!!! Kevin: When did you become such a baby?! (walks off) Sensitive Ben: Well, it hurt! (whining)
Immature Ben: (yelling to Julie's tennis opponent) Hey, other girl! You're a terrible tennis player and my girlfriend's gonna kick your butt! (silence, then the crowd starts yelling) Referee: What's happening up there! Julie: Uh, that's my... boyfriend. Referee: (sarcastically) You must be very proud.
Humungousaur:(singing) Humungousaur! Kevin: Never do that again. Humungousaur: Just trying it out.
Kevin: Ben! You've always been kinda girly but today... Intimate Ben: Yeah? Kevin: You're creeping me out! Intimate Ben: ...I understand, I'm truly sorry. Kevin: Stop understanding. Stop apologizing, stop talking about your feelings! I just wanna find some Forever Knights and pound them. Intimate Ben: Hmmm... Interesting. Kevin: Cut that out!
Forever Knight 1: Right then, we go in fast, grab what we came for and get out. Forever Knight 2: Charging the cannon now. (The Knights aim the tank's cannon at the museum door) Forever Knight 1: This'll rip that door open like it was made of tissue paper! Rath: (Rips open the top of the tank)LEMME TELL YA SOMETHIN', FOREVER KNIGHTS!! NOBODY'S RIPPIN' OPEN NOTHIN' EXCEPT RATH!!(One of the Forever Knights shoots at Rath)THATS YOUR FIRST MISTAKE; WHEN YOU SHOOT RATH, YOU JUST MAKE RATH MAD!!!!(Roars, and is about to attack when his phone rings and he answers it, lowering his voice) Helloooo? Gwen: Ben, where are you? Julie's in the middle of her set! Rath: Lemme tell ya somethin', Gwen Tennyson. I was on my way there when I saw this tank pull up at the museum and- Gwen: I don't care, get here! (Hangs up) Rath: That was harsh. (Raises his voice again)NOW, WHERE WERE WE?!!!(Looks back into the tank to find that the Forever Knights are running for their lives. Goes mad and starts throwing parts of the tank at the Knights. Talking to some old men on a bench who are acting as though nothing is happening) What?! It was already busted! (Walks off)
Reporter: Ben, any comment on Will Harangue's editorials? He says you're a menace! Immature Ben: Yeah? I say TV's a dead medium. (reporter looks disappointed/miserable) Sorry man, you know it's true! Girl: I'm your biggest fan! Immature Ben: Well, that makes two of us.
Gwen: Where have you been? Julie's match is about to start. Arrogant Ben: I'm here. Why don't you put a sock in it? Gwen: Whoa. What's with all the attitude? Arrogant Ben: A Ben classic. Miss me?
Kevin: If I weren't running for my life, I'd totally demand an explanation. (indicating the 3 Bens)
Ben: Nice game, Julie. Julie: How would you know? (walks away) Ben: What? What did I say? Gwen: It's what you did, Ben. You were late, and when you finally show up, you made a big entrance and completely blew her concentration. Ben: I can't help if I'm famous, right? (waves to the crowd; Gwen glares at him) I'm sorry. It won't happen again. Gwen: It better not. The finals are in three hours. That should be enough time for you to figure out how to make this up to her. Ben: (to Kevin) Any suggestions? Kevin: Yeah, there's a plan - ask me for girlfriend advice.
Ben:(Running to Gwen with Kevin behind him) Come on, Gwen, wait up! (Gets to Gwen, who turns around, and stops running) Okay, so I was a little late. I was kinda busy! Gwen:(Talking about Julie) And this tournament is important to her! Kevin: If we're doing important, shouldn't we finding out why the Forever Knights are try to bust into that museum? Gwen: Forever Knights? Like that's a big problem. They're trying to steal some piece of alien tech, so they can slay dragons or take over the world or whatever. Kevin: Oh, so now we just ignore them when they try and take over the world?! Gwen: They're always taking over the world, but this is Julie's first professional tournament! We should be supporting her, she should be the center of attention, especially from Ben. (Turns to Ben, who is pressing numerous buttons on his phone) What are you doing?! Ben: I was thinking that while we were waiting around, I could go and catch Sumo Slammers: The Movie. Kevin: You're either the bravest man alive or the dumbest. Ben: What? Kevin: Okay, the dumbest. Ben: It's opening today! And there's a 3pm show just a few blocks-! (Gwen puts his hand over his mouth) Gwen: No. Ben:(Moves Gwen's hand away from his mouth) But it's Sumo Slammers! In 3D! Gwen: Ben... Ben: It's their first live action movie! Everybody knows live action's better than cartoons! Gwen: Benjamin Kirby Tennyson! Don't even think about it! You can't be in two places at once! (Walks off, Kevin shakes his head at Ben, then walks off as well) Ben:(Stands still for a moment, then thinks of a plan) Or maybe I can...
Kevin: Ben, do something! Humungousaur: Why me? Kevin: Because you're a giant, indestructible dinosaur? Humungousaur: Okay, but shouldn't we work towards a consensus that lets us both feel invested in the plan?
Ben: (after obliterating the Forever Knight's armor into pieces) Rest in pieces!
Ben: There were aliens in Central America? Kevin: They came for the scenery, but they stayed for the chocolate.
King Urian: Who dares intrude? Forever Knight 1: It's Ben Tennyson, the alien changeling, and his lackey. Kevin: Oh, now I'm a lackey? Humungousaur: I'm sure he didn't mean to hurt your feelings. (to Forever Knights) You didn't mean to hurt his feelings, right? King Urian: Destroy them!
Ben 2: Where's the other us? Ben 3: What am I, a GPS?
When arrogant Ben steps out of the bathroom, the black "10" emblem on his jacket is white and the 10 is in black text. This is one of the most common errors of the series.
When Kevin absorbs metal, it was the same color as stone.
Naming and Translations
Spanish (Latin America)
Ben's middle name is revealed to be Kirby in this episode.
When the Echo Echoes turn into Ben, the personalities they display are similar to when Alien X is in use; Ben remains himself while his doubles are similar to Serena and Bellicus.
When Gwen was asking Arrogant Ben where he was after he exited the bathroom, he notes that this is a "Ben Classic". This is a reference to his arrogant and immature personality in the original series and the third season of Alien Force.
This episode is the 100th episode in airing order.