This episode starts out with Ms. Bitters telling the class about the big bang theory. Meanwhile Zim is watching the clock, waiting for one more second, but it seems to be stuck, due to a bug in between the gears. The bug finally got squashed, and the bell finally rings. Ms. Bitters is telling everyone not to forget that tonight was parent teacher night, and everyone is required to go, but Zim says he never agreed to go, but Ms. Bitters shows him a clip of them in class. She asks Zim if he was coming to parent teacher night, and he said yeah, not paying attention to what she just said. Dib said that he was putting up a major fight, and said he bet he didn't even know what parents were. Zim has a flashback of when he was born, a robot arm takes a bottle where baby Zim was stored and smashes it, creating Zim. Baby Zim said that he loved you, robot arm. Zim said that he will bring his parents, and they will be the greatest, most parent parents ever.
At Zim's house, a woman walks up and rings the doorbell, signaling the roboparents to come to the door. The robo-dad answered the door with, "Welcome home son," and the woman asked if the lady of the house was in. The robo-man came to the door. Then GIR starts walking by, and sees the womans bag of makeup. She tells robo-mom that she is selling makeup, and the robo-mom takes out a toothbrush and tells the woman to brush her teeth, and takles her to the ground with the toothbrush.
Zim comes walking around the corner thinking about what Dib said about his parents. He gets to his house, and he sees robo-mom brushing the saleswoman's teeth. The woman breaks free and runs, and GIR runs after her saying that he needs stuff. Zim walks in and robo-dad says welcome home son, and robo-mom asked if he wanted dinner, and pours flour on Zim. Zim sits on the couch, saying that he can't use the parent decoys, because their interactive skills are too limited, and then he calls GIR. GIR comes flying down from the ceiling with makeup on, and Zim tells GIR that they must program their parents to learn human social behavier, if they must join him for parent teacher night.
Zim has the parents in his lab, and he makes them watch a whole bunch of different TV shows. An Asprin commercial comes on and a man is walking down the street, when his spine cracks, and he falls to the floor have a seizure or something. The scarey monkey show comes on and GIR wants to watch it, but Zim puts in a movie thingy. Zim leaves GIR to make them watch the whole thing, but GIR turns it off. A diharrea commercial comes on, and the show "poke of doom" comes on. Zim and his parents are about to go, and robo-mom asks if he's ready. They both say that they are proud of him, and his dad hears GIRs voice saying that he loves this show.
It's time for parent teacher night to start, and all the kids are hanging out together. Dib and Gaz are walking together, and above them is a floating tv screen, with professor membrane on it. Dib explains to Mr. Elliot, Gaz's teacher, that he is too busy to be there, so he is transmitting live from his lab. Zim and his robo-parents walk in and Zim finds Ms. Bitters in a semi-circle of parents. Zim introduces his robo-parents to her, and he tells her that he loves them with all his heart, and that he needs punch now. Ms. Bitters tells the other parents that when she taught them, they would amount to nothing, and she said that she was right, they are nothing.
Dib sees Zim getting punch, and he introduces Zim to his dad as the alien, and professor membrane asked what country he was from. Zim replied with, "yes, yes, that's fasinating," ran off, ran back, and hit Dib's cup so that the punch splashed in Dib's face.
One kid's mom was talking to the robo-mom about her kid getting off the soccor team for crying to much, and robo-mom said that grass stains sure were tough to get out of soccor uniforms. Robo-dad said that he's sure that his kid would find something he was good at. Zim got pleased at this remark. The kid's dad offered robo-dad one of his wife's cookies, and he ate it, and doubled over in pain. Robo-mom asked what it was, and he said it was diarrhea. She said that she had just the thing for that, and she hit him in the face with her punch glass. Robo-mom looked at the lady she was talking to, asked who does her hair, and started poking her. Zim told her that he thought it was time to go home, and she told him not to tell her what to do, told him to go to his room, and picked him up and put him in the punch bowl. Meanwhile robo-dad was running into the wall. Mr. Elliot asked Zim if his dad was ok, and Zim said that he was perfectly fine. When robo-dad ran into the wall the last time, his arm fell off, and Mr. Elliot started screaming like a girl. Robo-dad started screaming about his squeezing arm, meanwhile, robo-mom was poking the other mom in the head still. Zim walked to robo-mom and told her that it was time to go. She asked if he was upset, and he said yes, and both robo-parents started doing the riverdance. To get them to stop, Zim said that he hurt his spine, and started screaming, and robo-mom said that it was time to take him home. To get home, they used their rockets to fly out the window, but, to Dib's unsurprise, no one saw it. He got mad and threw his punch on the floor, and one parent yelled that he was throwing punch.