This episode begins in Dinner in Elmore Mall where Gumball and Penny are having a date, eating ice cream. Gumball assumes that he cannot get brain freeze, but before he can finish his statement, he does, and Penny has to un-freeze him in the bathroom. As the two walk out, Gumball sees Rob at the hardware store and gets excited, asking if Penny knew about him which, as revealed by Gumball talking about his nemesis constantly in a series of flashbacks, she does. He tells Penny to relay him what Rob is doing, though it seems to indicate contrary to the notion of him wanting to terrorize Gumball.
Gumball then gets a threatening message from Rob, though it turns out the message was actually intended for Banana Joe. Gumball tries to rationalize the text as a mistake and confronts Rob, who reveals that he no longer wants to be Gumball's nemesis, instead opting to pursue Banana Joe because he is easier to hate.
The next day, at the Watterson's house, Penny tries to console Gumball about Rob's new nemesis relationship, but Gumball refuses to accept the reality. As they speak, the doorbell rings. Gumball assumes it to be Rob and, despite Penny trying to stop him, meets Rob at the front door regardless. It turns out that Rob wanted to return Gumball's stuff to him, hurting Gumball even further. As Rob walks away, Gumball tries to serenade him by holding a boombox with a song he once hated, though it does not work, and Rob does not hate the song as he once did.
The scene cuts to Rob spying on Banana Joe, ready to destroy him with a trap, but before he can do so, Gumball appears and distracts him. Rob tries to ignore Gumball's pleas for attention, but as he is about to cut the rope of his trap, Gumball takes his scissors, thus ruining the whole plan. The trap fails, but instead of yelling at Gumball, he leaves, making Gumball feel disappointed.
Next, Rob goes to Joyful Burger to give Banana Joe a burger rigged with explosives. Rob waits for Banana Joe to eat the burger, but he repeatedly stalls, much to Rob's chagrin. As Rob waits, Gumball appears dressed in a banana suit. He assumes that Rob hates Banana Joe because he is annoying and tries to level the playing field by mimicking Banana Joe and noisily sucking a straw. Still ignored, Gumball tries to push Rob even further by doing the Banana Dance. It instead captures the attention of Banana Joe, who gives Gumball a letter stating that, by doing the song and dance, he was breaching on intellectual property rights. Rob gets mad that Banana Joe did not touch the burger or allow him to deliver his quip. In an attempt to appease Rob, Gumball frantically eats the burger, subsequently exploding.
Back at the Watterson's house, Gumball complains about how all the cool people have nemeses. Darwin brings up the fact that he has one of his own: a hat. Penny tells Gumball he should simply accept it and turn over a new leaf, becoming friends, though Gumball steals the words right out of Penny's mouth, declaring them his own, and sets out to unite with Rob.
At Banana Joe's house, Rob is spying on Banana Joe with binoculars when Gumball pops up in front of him. He asks Gumball why he was here, and Gumball states that he only wanted to help. Rob decides to take up Gumball's offer. Gumball then tells Rob that he had booby-trapped Banana Joe's house, much to Rob's excitement, though it instead turns out to have been Tobias'. Rob then reveals a trap of his own: he had rigged Banana Joe's front door handle beforehand so that when Banana Joe opens the door to take out the trash, it will unhook the latch of a truck, sending oil barrels hurling towards him. Right as the plan is in motion, however, Gumball takes out his phone to snap a picture, but instead turns on the torch by accident, causing Banana Joe freeze in place. The oil drums hurdle by Banana Joe, leaving him unharmed but in shock.
Rob gets angry and he tries to shut off Gumball's phone, but quickly hides when Banana Joe approaches. Banana Joe asks what Gumball was doing behind a bush, and Gumball says that he was just chilling out with Rob. Rob emerges from the bushes, angry. He finally snaps and screams at Gumball in anger, declaring him the most insufferable, annoying, selfish person that he had ever met. He proceeds to throttle Gumball, much to his delight.
At school, Gumball tells Darwin that he just needed to keep the hatred interesting. He also tells him about how he smoothed things over with Penny, having locked Alan in her locker and written apologies all over him and her stuff. Seeing that Darwin has the hat on, he congratulates him on having smoothed things out as well. However, it turns out that Darwin was completely unaware of the hat and freaks out when he discovers it, ending the episode.
[Episode opens on a exterior shot of Elmore Mall. The camera cuts to Dinner, where Gumball and Penny are having ice cream. Gumball is eating his at a high speed]
Penny: Gumball, slow down. You'll get brain freeze.
Gumball: I'll be fine. It's my special skill. I can eat as much ice cream as I want and never get--
[Scene cuts to the bathroom. Penny is holding Gumball, whose head is frozen in a block of ice, under the hand dryer]
Gumball: --brain freeze. [Looks around] Uhh... how'd we get here?
[They leave the bathroom]
Gumball: So, how about an ice cream?
Penny: [Sighs in annoyance]
[Gumball sees Rob and gasps, darting behind a payphone]
Gumball: It's my mortal enemy, Rob! Do you think he saw me? Have I ever told you about Rob?
Penny: Yeah, once or twice.
[Flashback to Penny's birthday. As Patrick, Mrs. Fitzgerald, and Penny's sister try to sing happy birthday, Gumball is talking over them]
Gumball: And then Rob tried to blow up the dam, and then he said "I am your nemesis!" but in a cool British accent that I actually gave him.
[Flashback to Gumball and Penny on a roller coaster]
Gumball: This reminds me of that time the bus went through the tunnel as Rob tried to blow it up, but obviously I thwarted him by wrestling on the wing of a plane.
[As Gumball goes on, Penny gets off the ride, bored; Cuts back to the present day]
Gumball: And then I saw Rob in the mall and explained to Penny about how like, Rob's my nemesis.
Penny: [Irritated] Yeah, Gumball, that's right now.
[Gumball peers out from behind the payphone and spots Rob by Larry's Hardware Store]
Gumball: [Gasps] He's gone into the hardware store! He's probably getting stuff for me, you know, stuff to destroy me with. Oh my gosh, he can't see me here! [Hides again, pushing Penny into the open] What's he buying? Oh, don't tell me. No, tell me! No, don't tell me! Just give me a clue. Okay, two clues!
Penny: Mmm... he seems to be buying a circular saw.
Gumball: [Squeals] Is the blade diamond edged?
Penny: No, just a regular blade.
Gumball: That's okay, we're not there yet.
Penny: Wait! He's leaving. I think he's getting a coffee.
Gumball: Looks like someone wants to stay up all night creating plans to destroy me.
Penny: It's decaf.
Gumball: Oh... Looks like someone wants to sleep well so he can wake up early and create plans to destroy me.
Penny: What is it with you two?
Gumball: We're nemesises. Nemesisses? Nemesis?
Gumball: You wouldn't understand.
[Gumball's phone buzzes, and he checks it]
Phone: You have one unread threatening message.
Gumball: [Squeals] It's from Rob! I'm too excited, you read it!
Penny: [Sighs in annoyance as she takes the phone] "I hate you more than anything in the world."
Gumball: [Gasps and puts one hand on his face]
Penny: "I'm gonna smoosh you out of your yellow skin."
Gumball: [Gasps and puts his other hand on his face] Okay, he's color-blind. He never mentioned that before, but secrets are fine!
Penny: "I hate your slimy bananary guts."
Gumball: [Gasps and brings his foot up to the side of his head] It's a bit weird to call my guts bananary, but let's just go with it.
Penny: "You are my nemesis, Banana Joe?"
Gumball: [Kicks himself in the face and gets up after falling down] It's a weird new nickname for me, but it's still good to know he's thinking about me.
Penny: I don't think that message was for you.
Gumball: It's obviously just some sort of mistake. [Shakes his head in denial and starts walking] I'll just ask Rob.
[Gumball moves with an unusual gait, and Penny follows him]
Penny: Are you okay? You're walking kinda strange.
Gumball: No, this is my normal, casual walk and my normal, casual whistle.
[He begins whistling, then increases his speed to catch up to Rob]
Gumball: Oh, hey Rob. You didn't see me there.
Gumball: [Laughs nervously] You'll laugh at this. I got a threatening message from you, and uh, Penny here says it isn't for me.
Rob: Oh, you got that message. This is awkward... um, that-that wasn't for you.
Penny: Told you.
Rob: [Apologetic] Yeah, I-I should've let you know. The thing is, I'm nemes-ing someone else now.
Gumball: [Blushes in embarrassment] What?
Rob: Yeah, that message was for Banana Joe. He's kinda my new nemesis.
Gumball: [Voice breaking] You're not making any sense!
Rob: Look, I try to end you, you try to end me. You save me, I save you. It got complicated. I need something more simple right now.
Gumball: Oh, and Banana Joe is simple?! Okay, so I'll give you that. But I thought we had something!
Rob: I guess you and I just kind of... drifted together. Banana Joe's just easier to hate.
[Gumball bites his lip and whimpers]
Rob: You gonna be okay?
[Gumball continues to whimper; The background lighting dims]
Penny: Gumball? Gumball!
Gumball: [Feebly] I'm fine.
[The mall is now dark and empty. Penny sighs, picks up Gumball, and carries him off]
Exes and Foes
[Back at the Wattersons' house, Gumball is his bedroom with Penny]
Gumball: [Upset] He doesn't want to be my nemesis anymore!
Penny: [Consoling] Well, I'm sure he still hates you. He's just not... in hate with you.
Gumball: I just don't want to go back out there on the hating scene.
Penny: Don't worry, I'm sure there's someone out there that wants to destroy you. Irate neighbors, outraged friends, humiliated teachers, the list is endless.
Gumball: And with Darwin away too, I just... feel so neglected.
Darwin: [Standing in his fishbowl] I'm not away. I've been here the whole ti--
Gumball: You've got no idea what it's like to feel under-appreciated!
Penny: I think I do.
Gumball: [Gasps] Maybe it's Rob!
Penny: [Grabs his shoulder] Gumball!
Gumball: But it could be him!
[Darwin suddenly swaps places with Gumball, and is wearing his clothes. He smiles awkwardly at Penny]
Darwin: How did he do that?
[On the front porch, Rob is holding a large box. Gumball peeks through the window, then heads outside while pretending to be on the phone]
Gumball: Oh, yeah-yeah-yeah, sure. Uh, so I'll see you at three tomorrow for you nemesis interview, um... Pied Piper?
Rob: Really, the Pied Piper? That's the best nemesis you could come up with? I don't even want to get into the fact that you're only wearing underpants and speaking into a TV remote.
[Gumball presses random buttons in his attempt to turn off the television, and drops the remote]
Gumball: What can I do for you?
Rob: Seeing as I'm now someone else's nemesis, I don't really need this stuff anymore. [Hands the box to Gumball] It's some photos of you taken on long-distance lens, batteries from your smoke alarm. You know, that kinda thing.
Gumball: Oh, thank you. I'll just check it's all here. [Turns away, buries his face in the box, and cries briefly] Yep, that all seems to be in order.
Rob: [Tense] Right. Anyway, I better be going.
[As Rob leaves, he hears music coming from a boombox that Gumball is lifting above his head]
Boombox: Standing right here.
Rob: [Looking back] Huh?
Boombox: Right in front of you, babe.
Rob: Uhh, what are you doing?
Gumball: [Tears stream from his eyes] You used to hate this song.
Rob: Hm. Not anymore.
[The music continues as the screen fades to black. Next, Rob is shown observing Banana Joe through binoculars]
Rob: [Chuckles] That's right, straight into my trap.
[Rob peers at the rectangular shadow in Banana Joe's path, then up at a platform of bricks suspended by a rope. He lowers the binoculars and prepares to cut the rope]
Gumball: Hey, Rob.
[Gumball is seated on a bicycle nearby]
Gumball: Whatcha doin'?
Rob: Uh, I'm kind of in the middle of something.
Gumball: I see you got some scissors there. Well, I was gonna ride my bike through some heavy traffic. It would be terrible if someone were to cut my brakes.
[Rob glances at Banana Joe, who is almost in range of the trap]
Gumball: Yep. That would be super dangerous if somebody did that. I'd be obliterated. I mean, there'd be nothing left of me.
[Banana Joe steps directly under the platform, but Rob no longer has the scissors]
Gumball: They'd have to use my dental records to figure out who I was. [Spins the scissors around his finger] Yeah, it would be terrible if someone, you know, cut my brakes.
Rob: [Sees that his plan failed; Sighs] Never mind. [Walks off-screen]
Gumball: Rob? Rob?! Rob?
Yellow Guy: Excuse me? I don't mind cutting your brakes.
Gumball: [Repulsed] What? Weirdo!
[Gumball peddles away on his bike]
Cease and Desist
[Banana Joe is sitting at a table in the Elmore Mall food court. Larry approaches and places a hamburger in front of him]
Larry: And here's your burger, sir.
Banana Joe: But I didn't order one.
Larry: It's from a secret admirer.
Banana Joe: Oh! How nice!
[He starts to eat the burger, while Rob watches from elsewhere]
Rob: That's it. Just one bite, and it's bye-bye--
Banana Joe: Oh!
Banana Joe: Mustn't forget to take out the pickle. [Removes the pickle and resumes eating]
Rob: Just one bite, and it's bye-bye--
Banana Joe: Oh!
Banana Joe: Mustn't forget to take out the onions. [Removes the onions]
Rob: Just one bite--
Banana Joe: Oh! Mustn't forget to take out the sesame seeds. [Picks off the seeds individually] One, two, three...
Gumball: What's he got that I haven't?
[Gumball appears beside Rob, wearing a banana costume]
Gumball: Is it his voice? Is that it? 'Cause I can change. I can do his voice, easy. [Mimics Banana Joe] Hello Rob, I'm Banana Joe. I'm the poor man's Gumball.
Gumball: Look, I can be annoying.
[Gumball grabs a cup next to him, and proceeds to slurp through the straw. He increases the volume of his slurping in an effort to invoke a reaction from Rob, but ends up inhaling the straw by mistake]
Gumball: [Coughs out the straw] Ha! That's gotta be annoying, right? Hit with a spitty straw right in the face! That's gotta be ex-straw-dinarily annoying.
Banana Joe: Twenty-one...
[Rob continues to ignore Gumball]
Gumball: Oh come on! That joke was terrible! Fine, you want me to go full Banana Joe? 'Cause I'll do it! [Sings and performs the Banana Dance]
[Banana Joe gives him an envelope and marches off-screen. Gumball opens the envelope and reads the letter as Rob comes out of hiding]
Gumball: Apparently making terrible jokes, jumping around, and replacing song lyrics with the word "banana" is a breach of intellectual property rights. Ay caramba!
Rob: Argh! I can't believe it!
Gumball: [Gasps; Hopeful] You're annoyed at me?!
Rob: [Livid] No, Banana Joe! He makes me so angry! All that planning, and he didn't touch the burger! Or even let me finish my supervillain quip! [Chases after Banana Joe]
Gumball: It was gonna be, "Bye-bye, banana," right? I'll eat the burger! Look! [Hastily retrieves the burger and takes a mouthful] Oh. It didn't do any--
[He is immediately engulfed in an explosion]
My Hate Will Go On
[Gumball is in his bedroom again, along with Darwin and Penny]
Gumball: What am I gonna do? All the cool guys have nemesesies.
Penny: Like who?
Gumball: That boy wizard who had that creepy ginger dude following him around.
Penny: That wasn't his nemesis.
Gumball: Really? He never helped.
Darwin: I've got my nemesis.
Penny: [Giggles] Who?
Gumball: Don't get him started.
[Darwin glares at a blue baseball cap that is lying atop the wardrobe]
Gumball: Dude, it's a hat.
Darwin: That's just what he wants you to think.
Penny: [To Gumball] Maybe you should just accept it and turn over a new leaf. I mean, it's not like...
Gumball: [Inner voice] Maybe I should just accept it and turn over a new leaf.
Penny: You guys should just be friends.
Gumball: [Inner voice] Maybe we should just be friends! [To Penny] Don't worry, I came up with a much better idea while you were blabbering on. Me and Rob are gonna be friends.
Penny: [Peeved] That is literally what I just said.
Gumball: Aww, we make such a great team.
[Outside the Bananas' house at night, Rob is using night-vision goggles to spy on Banana Joe through a window]
Banana Barbara: Joe sweetie, when you're finished dancing to no music, don't forget to take out the trash.
Banana Joe: Okay, Mom!
[Gumball pops up directly in front of Rob]
Gumball: Hey buddy!
Rob: [Screams] What?!
Gumball: Oh nothing. Just wanted to hang out. You know, like friends?
Gumball: Yeah, I'm just here to help.
[Rob sighs, then resumes using the goggles]
Gumball: I booby-trapped his house.
Gumball: I booby-trapped his house. To help a buddy out. You know, buddies?
Rob: [Intrigued] Oh. When's it gonna go off?
Gumball: [Hushed] Any minute now.
[Rob looks on in anticipation for several seconds]
Gumball: So... why are we watching this house?
Rob: Because it's where Banana Joe lives?
Gumball: Oh, then who's house did I--
[There is an explosion off-screen, and an injured and burning Tobias flies overhead]
Tobias: WHY?! [Lands with a thud]
Gumball: [Indifferent] Oh, Tobias.
Rob: Never mind. I've rigged Banana Joe's front door handle so that when he opens it to take out the trash, it unhooks a latch on the back of the truck down the street, releasing the oil drums, which will roll down the sidewalk towards him. So just as he lifts the lid, he is obliterated.
Gumball: Wow. You really explained that in a lot of unnecessary detail.
Rob: Shh. Here he comes.
[The door opens, setting off the trap exactly as Rob described. Banana Joe whistles as he walks to the garbage can, and the barrels get closer. A sudden flash of light stops him in his tracks, causing him to narrowly avoid the out of control barrels]
Banana Joe: Huh? [Notices the aftermath; Gasps]
Rob: Agh, what are you doing?! Turn it off!
[Gumball has his phone's flashlight activated]
Gumball: [Panicking] I was gonna take a photo but I switched the torch on by mistake!
Rob: What is wrong with you?! [Ducks behind the bush as Banana Joe approaches]
Banana Joe: Did you see that?
Gumball: Uh, yeah.
Banana Joe: [Perplexed] So... What are you doing?
Gumball: Just chilin' with my buddy, Rob. In a bush. Right, Rob?
Rob: [Stands up, enraged] What is wrong with you?! You just ruined the whole thing for me again! I don't believe it! You've got to be the most insufferable, annoying, selfish person I've ever met!
Gumball: [Whispers] Go on.
Rob: In fact, I think I really, really, REALLY...
Gumball: Say it.
Rob: HATE YOU!
[Rob snaps, grabs Gumball, and violently shakes him while he smiles in contentment. The camera pans upward to the night sky, and a shooting star streaks by. The next day, Gumball is at school, putting a book into his locker]
Gumball: You see, Darwin? It's all bout keeping the hatred interesting. I mean, it's no big deal, but he did say he'd hate me forever.
[Gumball closes the locker, then heads down the hall with Darwin, who is sporting a blue baseball cap]
Darwin: [Impressed] Wow! That's a big commitment.
Gumball: I've smoothed things over with Penny as well. I couldn't find any cards that said, "Sorry I spent all this time ignoring you because I was trying to get some dude to hate me."
Darwin: So what did you do?
[Up ahead, Penny opens her locker and is shocked to discover Alan inside. The words, "I'm Sorry" are written on him and her school supplies]
Alan: [Gasps] Thank goodness! I couldn't breathe in there!
Gumball: Yeah, I couldn't find any balloons either. So, it looks like you made up with your nemesis too.
Darwin: What do you mean?
Gumball: The hat?
Darwin: [Realizes it is on his head] HE'S GOT ME! [Runs away screaming]