Phineas und Ferb bauen einen riesigen Irrgarten. Candace stolpert - während sie ihren Brüdern hinterher hetzt - auch in diesen Irrgarten. Während Isabella ganz stolz ein neues 'Fünkchen' (Namens Melissa) in die Welt der Pfadfinderinnen einführt, gibt Candace mächtig mit ihren 50 gewonnenen Pfadfinderabzeichen bei Melissa an und glaubt, sie könnte Isabella und Melissa aus dem Irrgaten führen. Als es jedoch ziemlich brenzlig wird, gibt sie zu, dass Isabella ihr bei den 50 Abzeichen geholfen hat und Isabella ist die Heldin des Tages, nachdem sie die drei aus dem Irrgarten führt.

Phineas und Ferb wollen eine Touristenattraktion für Danville bauen - sie errichten deshalb ein Gebäude, das bis zum Mond reicht. Doofenshmirtz dagegen will den Mond drehen, da er glaubt, die dunkle Seite des Mondes könnte konkurrierende Bösewichter, wie z.B. Werwölfe, ausschalten. Bevor Candace ihrer Mutter das riesige Gebäude zeigen kann, dreht sich der Mond und der Garten ist wieder leer. Doofenshmirtz muss erkennen, dass sein Unternehmen zwecklos war, da die dunkle Seite des Mondes lediglich der Schatten der Sonne ist.

Candace und die Prinzessin von Druselstein tauschen für einen Tag ihre Existenzen, da sie sich zum Verwechseln ähnlich sehen. Währenddessen bauen Phineas und Ferb eine riesige Jukebox. Gleichzeitig versucht Perry, Doofenschmirtz daran zu hindern, die Eröffnung des neuen Opernhauses des Bürgermeisters zu ruinieren.

Um Isabella und den Pfadfinder-Mädels bei der Erlangung ihrer Pfadfinder-Abzeichen zu helfen, bauen Phineas und Ferb eine Biosphäre.

It's Phineas' birthday and for the special occasion, Ferb puts together a clip show of the gang's favorite moments. Meanwhile, Agent P has to stop Dr. Doofenshmirtz from using his 'non-inator' to pre-empt his brother's biography from appearing on television.

When Candace discovers that Phineas and Ferb have invented a computer that can answer anything, she asks it how she can finally bust her brothers once and for all. Meanwhile, Dr. Doofenshmirtz loses the key to his latest invention, the "All Purpose-inator," and Agent P must find it before he does.

Mom joins Jamie Oliver as one of the judges for Danville's Meatloaf Festival Cook-off, as he stresses healthy eating and fresh ingredients. Meanwhile, Candace puts a bid on a prized souvenir resembling band members Nigel and Adrian from her favorite band, Tiny Cowboy, at the Rock and Roll Memorabilia Auction, but gets distracted when her brothers build a bounce house in their backyard. On the other side of town, Dr. Doofenshmirtz has plans to enter his family meatloaf recipe into the competition using "hate" as the special ingredient.

Als Phineas und Ferb erfahren, dass jeder in Baljeets Familie bereits bei Fahrradrennen verloren hat, bauen sie eine Rennstrecke und helfen Baljeet zu gewinnen. Währenddessen plant Candace, die Jungs endlich mit Hilfe ihrer neuen Videokamera dranzukriegen, aber Dr. Doofenshmirtz' Pop-Up-Inator durchkreuzt ihren Plan.

It's Halloween night and the kids encounter a strange boy named Russell who is convinced his house is haunted. Meanwhile, Dr. Doofenshmirtz's disdain for grass causes him to invent a "mind-transfer-inator" enabling him to merge minds with a cow and destroy all the grass in the Tri-State Area. Unfortunately, his plan backfires and he transforms into a scary "were-cow" that wreaks havoc any time there is a full moon. It's now up to Agent P to stop him and save Danville.

When Phineas and Ferb are inspired by an antique escape chamber that Dad acquires, they decide to build a computer-controlled tower that will trap them inside and allow them to explore the world of escapement. Meanwhile, Dr. Doofenshmirtz invents a "Rude-Inator" to ruin Roger's meeting with a visiting dignitary from England.

After locating and retrieving the Amulet of Juatchdoon, adventuring archeologist duo Ohio (Phineas) Flynn and Rhode Island (Ferb) Fletcher set off to South America to help Damsel in Distress Isabella find the Lost Temple of Juatchadoon and her missing mother. However, Dr. Doofenshmirtz has other plans for the amulet - to awaken the evil corn colossus to give him the power to destroy the world.

When Mom is out of Doonkleberries for her famous Doonkleberry pie, the boys set out to find some for her. Meanwhile, Perry and Dr. Doofenshmirtz find themselves across the ocean as Doofenshmirtz returns home to renew his Druesselsteinian driver’s license. Back in Danville, Candace is convinced she has discovered the answer to her busting problem.

When Baljeet becomes concerned that he is losing his mental edge, the boys invent a cerebral stimulatory hat, or "Brain booster," to help him. But when the hat exceeds expectations and makes Baljeet exponentially smarter, he suddenly views everyone else as beneath him and becomes a threat to civilization by taking Earth's atmosphere and bringing it to the moon. Meanwhile, Dr. Doofenshmirtz plans to use his "Key-Find-Inator" to collect all the keys in Danville in hopes that it will lead to the Key to the City.

Candace finds it difficult to bust Phineas and Ferb when her brothers build nanobots that can assemble into any object they can imagine. Meanwhile, Dr. Doofenshmirtz has jury duty, so Norm takes over the day’s evil scheme -- to destroy Danville by using weapons.

The Flynn-Fletchers are off on an African safari, leaving Perry at home to deal with Doofenshmirtz and his most evil plot yet: to take over the O.W.C.A. But when Doofenshmirtz accidentally zaps Carl the intern with his Ultimate-Evil-Inator ray, Carl takes over the O.W.C.A. (Organization Without a Cool Acronym) and imprisons Doof and Monogram. Agent P steps in but gets zapped with Doof’s many rays and in the cliffhanger of all cliffhangers, disappears.

Candace fordert Buford heraus. Er soll es schaffen, dass Phineas und Ferbs Erfindungen nicht in letzter Sekunde verschwinden. (Text: Sky)

Isabella and the Fireside Girls turn themselves into bees. Poofenplotz tries to become Queen of the World by stealing and consuming massive amounts of royal jelly.

The boys set out to prove the existence of the elusive Chupacabra to the world, but Candace can't stand the wait and needs to first just prove it to Mom. Meanwhile, Doofenshmirtz has the brilliant idea to use his Switch-Place-Inator to remove hair from one person and give it to another so that he can in turn sell his hair growing tonic.

The gang switches bodies with alien tourists for a free intergalactic vacation.

After studying hours of horror movies, Doofenshmirtz develops a theory that enlarging small, cute animals into giant beasts will help him take over the Tri-State area. But when he puts his plan into action, he soon realizes it might be too much for him to handle. Meanwhile, Phineas and Ferb make a giant revolving foam city so they can safely perform skateboarding tricks, and Candace's tour of the Danville Space Laboratory gives her an opportunity for a high-tech bust.

Es geht wieder auf Zeitreise! Wir befinden uns im 20. Jahrhundert, wo Phineas, Ferb und ihre Freunde Dampftechnik verwenden, um ihre Aufgaben im Haushalt schneller erledigen zu können. Auch Doofenschmirtz verwendet die neue Dampftechnologie, beim Versuch die Danville Weltausstellung von 1903 zu zerstören.

Phineas and Ferb have created a device reinforcing the wind and test them on a giant kites in the park. Candace thinks she's finally going to bust when Mom gives her backyard a makeover. Meanwhile, Doofenshmirtz builds a Water-Zalewator to celebrate his girlfriend of the past, who doused him with water, because Heinz she loved, but who then gave him the basket.

Doofenshmirtz's latest "inactor" turns Danville citizens into contagious zombies. Agent P. and the gang try to save the town and avoid becoming zombies themselves.

It's been 10 years after the events of the present, and Phineas must decide what university to go to. After discovering that Isabella had a crush on him for years, Phineas must reach her before she leaves for college and express his true feelings for her. Meanwhile, Doofenshmirtz has a mid-life crisis.

It's the last day of summer vacation and Phineas and Ferb decide to seize the day and make the most of it. Unfortunately for Candace this means it's also her last chance to bust her brothers... or is it?