Phineas and Ferb set up a roller derby rink for Grandma Betty Jo.

Phineas and Ferb decide to do absolutely nothing for the day. Candace questions her purpose in life after realizing that she can't bust her brothers for doing nothing. Meanwhile, Dr. Doofenshmirtz is tired of being the ugliest person around, so he invents a device that can turn anything and anyone ugly.

When Buford's goldfish goes missing, the boys help him find it out at sea. Meanwhile, Dr. Doofenshmirtz tries to destroy a tape of him 'saving' a kitten from a tree.

Phineas and Ferb build the world's largest bowling ball and pins. Meanwhile, Doofenshmirtz wants to use his latest invention to freeze the Tri-State Area so the people will buy his hot chocolate.

The guys decide to hold a competition between the girls to see which are better at sports. Also, the build a telescope in the backyard. Then, Jeremy's sister is tormenting Candace. Doofenshmirtz wants to be the winner of a dog show, and makes an attempt to liquefy a steak.

The boys build a telescope, while Doofenshmirtz tries to liquify steak. Meanwhile, Candace has another encounter with Jeremy's younger sister, Suzy.

Phineas and Ferb create the world's largest golf course, and since Candace is sick, she asks her best friend Stacey to bust the boys for her.

Phineas and Ferb create a teleporting machine, but it ends up switching Candace and Perry's brains.

When Django feels down for not being able to draw art on the same scale as his father, Phineas and Ferb get some big ideas for his piece and the famous "unpainted desert". Meanwhile, Perry faces off against Doofenshmirtz, as he does his best to impress his visiting evil professor.

The boys create a cartoon and cast themselves as superheroes and Candace as the villain, while Perry attempts to defeat Doofenshmirtz, who has taken control of the power of dance.

When Doofenshmirtz's brother Roger is elected mayor, he decides to build his own country, where he can rule over everything, but how will he stop him when Perry is having trouble entering his hideout? Meanwhile, Phineas and Ferb, in an attempt to help Isabella see her "first" rainbow, create the Rainbow-enator, which harnesses the power of their breakfast cereal to make the light show. The strangest anomaly of the episode, however, is when Candace and Vanessa manage to get their clothes mixed up at the dry-cleaners, resulting in a backwards day for everyone.

The boys build a rocket ship to get a good look at a star named for them, and Candace accidentally takes a ride with them just as she is trying to find the courage to ask Jeremy to a dance, while Isabella tries her best to do the same with Phineas. Meanwhile, Perry must stop Dr. Doofenshmirtz, who, not only is conveniently in space too, but has created a massive spacestation in an attempt to get revenge on "Huge-Hands-Hans".

Phineas and Ferb help Baljeet build a portal to Mars for a special Summer science fair. Candace competes against another girl for getting a job at Mr. Slushy Burger. Meanwhile, Doofenshmitz builds a bicarbonate volcano for the science fair, in yet another attempt to redeem himself from his embarrassing childhood, where we discover where the -inator suffix originated from.

When Candace believes that no one wants to be around her anymore, she quickly steps through Baljeet's portal to Mars, where she is quickly heralded among the martians. Meanwhile, Perry accompanies Dr. Doofenshmirtz to help build his evil contraption for him to stop faster, with slightly less than pleasing results.

Fed up with her brother's inventions always disappearing, Candace enlists the help of everyone in the neighbourhood to build and watch a big and obvious invention, that they might finally see exactly what happens to everything. Meanwhile, is it mime? No, it's Doofenshmirtz' new Invisibility Ray.