Billy and Mandy tell Grim it is "Opposite Day" and that, when they say something, they really mean the opposite. Due to his difficulty understanding the concept of Opposite Day, Grim has to do Mandy's chores. Finally, Grim thinks he understands when Billy and Mandy say they "want" pie, meaning they "do not want" pie. However, Mandy then says that when she said it was Opposite Day, it really was not.
When Zim comes home from a lousy day at skool because he found out that Dib knows a flaw in his security system, Gir attempts to cheer him up by rubbing bacon oil all over his face. However, when Zim develops a pimple due to the grease, he fears that he will be considered abnormal and that it will jeopardize his mission. Zim believe he can use some acne medicine to get rid of the pimple, but when it only gets worse and when Gir draws a little face on the pimple, Zim believes all hope is lost; though Zim soon discovers the pimple has hypnotic powers and he hopes to exploit this new power in order to get Dib to reveal his secret.
Zim is upset because all of the other Invaders are doing much better in their tasks than he is, though he inadvertently discovers that his signal to the data hub has been interrupted. When Zim takes a closer look, he discovers that the Earth has actually been hijacked by the Planet-Jackers, an alien race who must throw other planets into their dying sun in order to survive. Zim begins to formulate a plan to stop the Planet-Jackers, but when Dib refuses to believe him, he realizes that he must save the world he plans to destroy by himself, just for the sake of being the one who gets to destroy it.
When a family's home is threatened by the Corsola who live nearby, it's Ash and friends to the rescue...and maybe Misty can finally catch that Corsola she's been after!
When Zowie accidentally takes Olie and Billy's treasure, she does not tell them, causing the boys to suspect each other of taking it; Olie loses a toy his dad gives him; Zowie finds a flower that she tries to nurse back to health.
Ippo, a teenage boy with a pure heart and unrelenting determination, discovers a passion for boxing after veteran fighter Takamura saves him from bullies.
Chronicles of NFL teams' preparations for the season.
An inside look at NFL training camps. From the top coaches to the rookies trying to make the team, Hard Knocks showcases what it takes to be in the NFL.
Musical guest: Wynton Marsalis Hardy Lester returns and sues the family to get his half of J & H Groceries back, Ahmad's basketball coach is fired when his good intentions are misconstrued. Teri and Damon have a final confrontation.
Oswald is separated from Weenie when a drip coming from the kitchen sink eventually causes a city wide flood.
Meg lands an internship working with the school nerd at a television station.
Olie discovers rust in outer space; Polina is feeling all wound up; Olie and Billy race against Zowie and Polli.
Oswald and Weenie's banana seed produces a much bigger fruit than they expected.
Tyson determines to battle the blader named Oliver, but does he have any chance at victory?
When Jack mistakenly destroys a group of scientists' chance to escape Aku, he and the scientists join forces to try and fix the problem, hopefully returning Jack home as well.