Throughout the summer Phineas and Ferb and thier freinds had great adventures everyday, but when school is one day away, they're adventures may come to an end. Their only hope is to find the mystical stone of miracles, which is fortold to grant one wish, and wish for an endless summer, accompanied by their friend Isabella. Meanwhile, the housepet and secret agent Perry must stop long time nemisis Dr. Doofenshmirtz from finding the stone so that he may wish to rule the galaxy.
Phineas, Ferb, and all their friends are really sad as summer ends that day. Then Phineas decides that they should do the biggest thing ever! So, they try to combine some of their past projects but to no avail. Then Baljeet suggests they find the stone of miracles, which can grant one wish before dissapearing for 1000 years. Meanwhile Monogram tells Perry that he needs to get the stone of miracles and destroy it before Doofenshmirtz can get it. He arrives at the evil doctor's lair before being captured and handcuffed to a pole. Doofenshmirtz and Norm head out to get the stone of miracles so that Doofenshmirtz can wish to take over the tri-state area, build a time machine, and get the stone 1000 years later to rule the world ("I was gonna wish to rule the world but then I thought 'that's boring', so I decided the Tri-State area first")! He then races off with Norm and many of his past machines to get the stone. Meanwhile, Phineas, Ferb, and their friends load many of their things onto a rollercoaster and race off for the stone! At Doofenshmirtz Evil Incorporated, Perry picks the handcuffs, gets his jetpack out, and races to get the stone.Major Monogram pops up on his wristwatch and warns him that his owners must NOT see him. As Perry heads out on his hovercraft, something blocks out the sun. Doofenshmirtz had wished for a giant robot with the stone that's powered by the stone itself! Perry sees that in one hand Phineas, Ferb, and the gang have been captured. Before he knows it, the other hand swipes at him, and Perry sees his life before his eyes.
Perry wakes up in a place covered by clouds and sees the Platypus monster, Dr. Phineastein, and Ferbgor with haloes and angel wings. Suddenly, a vacuum pulls him into the real world. he comes to, seeing the gang about to be killed by Doof's robot. He springs into action and uses his hat to slice a frayed wire, incapcitating its arm, and the gang falls to the ground. Phineas sees Perry with his hat, thinking he's an Indiana Jones fan, but realizes that he's a secret agent. Phineas quickly manages, with a pipe, to knock the Stone out of Doof's hand. He saves it from falling down a gorge, but Doof grabs Isabella with the operational hand and holds her over the gorge. He presents Phineas with a choice: Give him the stone and "rule the galaxy together as scientist and kid," or watch Isabella die. Isabella screams, "Phineas, don't do it, please!" He replies, "I can't let him do this to you!" Doof rolls his eyes and says, "Puh-lease!" Phineas turns toward him and says, "Alright, I'll give you the stone, just don't hurt Isabella!" The arm drops Isabella in the robot, and Isabella gaves an Idea, she kisses Dr. Doofenshmirtz in the Cheek, and Doofenshmirtz have a Heart Attack and he drops on the floor. Dr. Heinz Doofenshmirtz, of Gimelstchump, Druselstein, is gone. Perry finds a slab of granite and encraves with his laser watch the words:
In Loving Memory
Dr. Heinz Doofenshmirtz
Born: c. 1970 Gimelstchump, Druselstein
Died: August 14, 2011 Danville, NY, United States of America
and then Isabella kisses Phineas, and all Hop in Perry's Hoverboard, and Major Monogram promise not to Tell anyone that Perry's a Secret Agent, or in a DEEP Doodie, and Phineas say "Whoa, What a Great Vacation, Vacation, we'll see in Christmas Vacation." On August 15, 2011, They enter to School, as Phineas is on the roof, Watching the Skies, as waiting for Christmas Vacation.
Star Wars: Doof's line to "rule the galaxy as scientist and kid" is similar to a line of Darth Vader's ("Join me and together we will rule the galaxy as father and son."). Also, in the Star Wars: the Clone Wars episode "Voyage of Terror," when Obi-Wan and the Dutchess of Mandalore were saying mushy stuff to each other, the bad guy, Tal Merrik, rolled his eyes and said "Please," somewhat sarcastically. This will not happen idiots!