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

While on an archaeological dig, the boys discover a caveman who falls in love with Candace, who is dressed as a cave girl for costume party. Then, Phineas and Ferb assist Buford in locating his missing goldfish.

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, Ferb, and Candace go to a Renaissance festival and Phineas and Ferb get Candace to go into a jousting tournament.

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

The boys are helping Ferb's grandfather live his life long dream - to jump a gorge in his motorcycle, the Holy Mackerel. Meanwhile, Perry sets out to stop Dr. Doofenshmirtz from exacting another petty revenge that dates all the way back to the sandbox.

When Isabella falls prey to hiccups, Phineas and Ferb gather the kids together to help scare them out of her, using a remote controlled haunted house. Meanwhile, Doofenshmirtz sets out to destroy his mentor's hideout, so that no one could discover his secrets, but not if Perry has something to say about it!

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.

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.

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.

When an early end to their daily project causes Phineas and Ferb to mistake an egg for Perry's, the boys use all their technological knowhow to help hatch the new part of the family. However Candace has different plans for the egg, as a nature show brings her to be the one to convince Phineas and Ferb that the newborn will need a real mother. Meanwhile, Doofenshmirtz is doing all he can to convince Perry that his latest scheme really is evil.

Buford has a new game, "Jump and Duck", which everyone is loving the look of. But Phineas is always one for a challenge, and Candace's comment about a game "sucking them in" is just the inspiration he needs to create a virtual reality machine of "Jump and Duck". The trouble begins when Candace, in her preparations for a Cotillion Jeremy has asked her to, gets pulled in before the boys. Meanwhile, Doofenshmirtz has a slightly more disturbing childhood horror revenge story, but is the song and dance really necessary for this one?

Phineas and Ferb set out to build a bigger plane than Howard Hughes' wooden Spruce Goose, so they build it out of papier-mâché, to do a similar theme to the Spruce Goose, complete with in-flight service and entertainment. Dr. Doofenshmirtz is doing his part to be green by using recycled materials to build an "Evaporator-inator" to dry up all the pools in the Tri-State area. Meanwhile, Candace and Stacy attend Jeremy's pool party only to discover an adventurous Australian girl is capturing Jeremy's attention.

After hearing that Jeremy was in a commercial, Candace wants to gain popularity as well, by going on Phineas and Ferb's TV game show.

Phineas and Ferb create an automatic carwash in order to raise money for Isabella and the Fireside girls.

Perry the Platypus is reassigned and forced to move to the Quad State area with a new family and battle a new villain, the Regurgitator. During his new assignment, Phineas, Ferb, and Candace put in every effort to find him, hoping he'll return to them.

To play a game of indoor hide-and-seek Phineas and Ferb shrink down their friends including, their new extreme fan, Irving. Meanwhile, Dr. Doofenshmirtz attaches a nanobot to Perry in an attempt to discover where he lives.

Phineas and Ferb build a ocean liner so that Baljeet can go on a romantic cruise with his friend Mishti, whom he now notices is a very pretty girl. Meanwhile, Doofenshmirtz wants to move all the lighthouses to the other side of town so that he can get a good night's sleep instead of hearing the constant noice from the boats surrounding the bay by his headquarters

Phineas and Ferb learn that Baljeet has signed up for rock camp and worries he may get his first failing grade. So the boys help by forming a band to help him express his feelings, especially for math. Meanwhile, Candace wonders why Jeremy doesn't give her a cool nickname as Stacy gets close to Coltrane, the rock camp director. Doofenshmirtz's latest plan has him wanting his own army of babies by broadcasting his heartbeat all over the tristate area.

When Candace finds a rabbit, she wants him as her pet, but in hindsight, he's actually a rouge agent trying to find Perry's secret lair for information. Meanwhile, Phineas and Ferb try to make x-ray glasses. And since Perry isn't around to stop his latest plot, Doofenshirtmz faces an unusual new foe.

Stacy has a spa day planned for herself and Candace, but they get side tracked when Jeremy is participating in a house-building program for the homeless and Candace joins as well in hopes of impressing him. Fortunately, the girls are able to get their spa day after all when Phineas and Ferb build their own spa with its own special features. Meanwhile, Doofenshmritz finds a cat which causes a lot of problems when he's trying to carry out his latest evil plot.