|“||With my stimulated brain, I am dreaming up all sorts of super smart projects.||”|
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 notices that the kids are up to something dangerous, even though it's just playing cards. Baljeet comes in, apologizing that he's late. Buford brings up the question of who invented playing cards. Baljeet claims that ancient Babylonians created playing cards, but Ferb corrects him by telling everyone that the Babylonian Society had been defunct for 1000 years before playing cards were introduced in India. Baljeet then realizes in horror that he was wrong, and concludes that due to the 3 months of Summer Vacation, he is losing his edge. After Baljeet walks away, Phineas says he knows what they're going to do.
At the antique shop, Lawrence is showing a customer around, and shows her a wardrobe that Perry is sitting near. After they walk away, Perry dons his fedora and walks into the wardrobe and into his lair, encountering coats, trees, and snow on his way. Major Monogram then explains the trees were left over from Christmas and that the air conditioning was on the fritz. He then informs Perry that keys across the Tri-State Area are disappearing causing chaos.
In the backyard, Baljeet comes back with two CAT Scans of his brain, one before Summer and one during Summer. Isabella points out that they look the same. Baljeet knows this, but says he is slipping, evidenced by the fact he took three minutes to remember how to give himself a CAT Scan. Phineas then shows Baljeet what they made while he was gone; a helmet that stimulates his brain. The helmet visibly works, as Baljeet performs complex equations to solve how many sub-atomic particles are on a dandelion. Meanwhile, Candace asks Stacy if she still wants to go to the pool.
Perry then appears at Doofenshmirtz Evil Inc., where Doofenshmirtz traps him in a water soluble capsule. He then reveals his plan; to steal all of the keys in the city with his Key-Find-inator, in hopes of finding the Key to the City, believing it will allow him to go anywhere in the city.
Back at Phineas and Ferb's house, Baljeet is still testing the helmet. He reveals his new intelligence has given him a lot of ideas, with his favorite being taking the Earth's atmosphere and placing it on the moon, so that everyone would have a better view out of a telescope. His friends try to talk him out of it, but he continues anyway. Phineas realizes that the brain booster was not such a good idea after all. Buford tries to shut off the helmet's power source, but Baljeet placed a force field around it so no one would shut it off.
Fooling Baljeet with cardboard effigies, Phineas, Ferb, Buford and Isabella make their way under the backyard to get to the atmospheric device. Using jet-packs, they distract Baljeet by flying around the device. Thinking he has stopped them with his tractor beam, Baljeet commences the atmospheric transfer process. Candace walks out, notices the device, and calls Mom, who is stuck at the post office because she can't find her keys.
As the weather grows erratic, the Key to the City ceremony is starting. Just as Roger hands the key to its recipient, the Key-Find-inator zaps it and brings it to him. Due to the rain, Perry is able to escape from the capsule and attack Doofenshmirtz.
Baljeet continues the transfer, as Phineas warns him to surrender. As he realizes that he was fooled by life-sized mannequins, Buford comes and yanks the brain booster off of Baljeet's head, and he returns to normal. Phineas explains that Baljeet was chasing the mannequins while they dug up through the device. Phineas asks if he remembers the mannequins they built earlier. Baljeet says he doesn't. Ferb says "It pays to be on time", prompting Baljeet to get an alarm clock. Realizing his mistake, Baljeet explains that he can't stop the transfer, as he does not remember the controls. Isabella asks if he included a fail-safe. He remembers he did, but he can't find the keys to shut it off.
The Key to the City arrives at Doofenshmirtz's -inator. While he was analyzing how it is more of a decoration, Perry reverses the affect of the -inator, sending all of the keys back where they were and causing it to self-destruct. Doofenshmirtz rants more about the key, then is zapped by lightning. As Linda continues looking for her key, it lands in her hand.
As Baljeet is running around frantically trying to find the key before the transfer is complete, it lands on the key hook. One second before the transfer is complete, Baljeet turns the key and stops the process, saving the Earth.
Isabella comments that they should do something about the helmet. Buford interjects; using the helmet, he created the world's largest wedgie machine. And as Candace was about to bring Mom into the backyard, the wedgie machine pulls the atmospheric device into space along with the helmet. Candace complains that the device was there just a second ago, with Linda saying that "It pays to be on time". She asks if anyone wants pie, and all of the kids run in. As Perry walks in, an annoyed and sad Candace says she's "Going to get an alarm clock".
Second verse of Big Brain.
|The image gallery for this episode may be viewed here.|
- It is revealed that Isabella could be no older than 10–13 years old, due to her saying, "I was so looking forward to junior high".
- Buford reveals that Phineas and Ferb have built over 150 inventions.
- The decoys that were frozen by Baljeet's tractor beam have a similar appearance to the ones Candace used while singing in Rollercoaster: The Musical!.
- Technically Candace would've busted Buford and Baljeet because Phineas and Ferb didn't build the invention.
- Second time Doofenshmirtz builds an inator to find a key ("Ask a Foolish Question").
- Fourth time one of Phineas and Ferb's inventions/big ideas goes bad ("Day of the Living Gelatin", "Escape from Phineas Tower", "Lotsa Latkes").
- Candace wears the same swimsuit as she did in "De Plane! De Plane!" and "Atlantis".
- This is the sixth episode in Season 3 and eleventh overall episode that Doofenshmirtz is seen in his underwear. ("Lights, Candace, Action!", "Tip of the Day", "Bubble Boys", "Phineas and Ferb Hawaiian Vacation", "Nerds of a Feather", "Run, Candace, Run", "My Fair Goalie", "Bullseye!", "Monster from the Id", "The Remains of the Platypus") Apparently, Doofenshmirtz prefers to strip himself to his underwear majoritorally in Season 3, alone.
- This is the second time someone's brain grows big, the first being Doofenshmirtz's and Perry's in "Phineas and Ferb Hawaiian Vacation".
- Second time an even smarter version of Baljeet is seen. (Phineas and Ferb The Movie: Across the 2nd Dimension)
- Third time Flynn-Fletcher Antiques appears. ("Phineas and Ferb's Quantum Boogaloo", "Escape from Phineas Tower")
- This is the second time Buford says something about a wedgie machine.("What Do It Do?")
- This is the second time Baljeet and Buford build inventions without Phineas and Ferb. First is Baljeet; he tries to stop Phineas, Ferb, Isabella, and Buford. Then Buford; he used the helmet to make the world's largest wedgie machine and try to stop Baljeet, and give him a wedgie. ("Phineas and Ferb Interrupted", "What Do It Do?")
- This is the second time Linda states she can't go anywhere unless something else happens first ("Thaddeus and Thor").
- Another time that someone questions how long their summer vacations is. ("The Curse of Candace")
- Second episode in which something has "Maximus" in the name. ("Gi-Ants")
- June 22, 2012(Family Channel)
- July 19, 2012 (Disney XD Germany)
- July 21, 2012 (Unitel Bolivia)
- August 10, 2012 (Disney Channel Latin America and Brazil)
- November 4, 2012 (Disney XD Spain)
- December 30, 2012 (Disney XD Latin America)
- January 7, 2013 (Disney Channel Portugal)
- January 17, 2013 (Disney XD Poland)
- March 2, 2013 (Disney Channel Asia)
- Playing cards actually originated in China, not India, so Ferb and Baljeet were both wrong.
- When Doofenshmirtz catches Perry, his shirt starts out white, but when he is putting his pants on, it turns black.
- Baljeet's pocket disappeared and reappeared throughout the episode.
- In the scene where Baljeet sees the decoy models of the gang, it's shown Ferb before Isabella but when the camera jumps to the backyard it's the opposite, and their gestures are different.
- Also, the tree is not seen. At the same time, the tape recorder is behind the decoys, but before that shot it was nowhere to be seen.
- When Baljeet is trying to stop Phineas and his friends a lever is out of place.
- Candace complains that the tower was here just a second ago, but the time between the wedgie machine pulls the tower into space and she says that is actually nine seconds in real time. (though she could've been exaggerating)
- When the song begins, at one point Isabella's right bangs are the same color as the sky.
- In the last shot, Candace's eyes repeatedly change color from black to blue and vice versa.
- Second time Doofenshmirtz sings Gitchee Gitchee Goo ("I, Brobot"), but this is the first time he's forgotten the lyrics.
- The Tallest tower from the Dark Side of the Moon was seen again. ("The Doof Side of the Moon", "The Mom Attractor")
- Circus Maximus - The episode title is an allusion of Circus Maximus, an ancient Roman chariot racing stadium and mass entertainment venue.
- The Lion, the Witch and the Wardrobe - Perry's lair entrance is the same as when Lucy enters the wardrobe and into Narnia. Also, Lawrence jokingly says that the closet at his antique shop had a secret land in it with mystical creatures, much like Narnia is.
- X-Men - Phineas and Ferb's helmet resembles Professor Xavier's helmet in Cerebro.
- Vincent Martella as Phineas
- Ashley Tisdale as Candace, Additional Voices
- Thomas Sangster as Ferb
- Alyson Stoner as Isabella
- Maulik Pancholy as Baljeet, Additional Voices
- Caroline Rhea as Mom, Additional Voices
- Dan Povenmire as Dr. Doofenshmirtz
- Jeff "Swampy" Marsh as Major Monogram, Additional Voices
- Richard O'Brien as Dad
- Dee Bradley Baker as Perry, Additional Voices
- Bobby Gaylor as Buford
- Additional voices: April Stewart, G.K. Bowes, Mo Collins, Sue De Nim
"De Mam Aantrekker"
"Jouw Achtergrond Verhaal"