When Phineas and Ferb's group of friends (Isabella; Bufford Baljeet and the explorers' troop) go on holidays, Phineas and Ferb feel alone so they invent a way of having new friends: to travel to other worlds, where they finish in Springfield and ask Homer if he has any children, the one who answers them with another question; Where is Perry? During a battle, the invention is destroyed and the nuclear energy creates hearts that float into the heavens; Lisa thinks that Ferb made it and kisses him. At last Phineas says that there would be a second part.