After Phineas and Ferb return from Avatar: the Last Airbender, they realize that all their freinds never came back from Disney World. On the other side of the universe, on the super star destroyer, Executor, Darth Vader has kiddnapped Isabella, Perry, Buford, and Baljeet after luring them to Disney World with a "free trip". This was all in an attemt to trap Phineas, who the Emperor wants. The boys turn their, "Go to another TV show" portal to a " Find our friends" portal. Once they step through the potal, Ferb is captured. Phineas is brought before Vader. He tells Phineas that unless he joins the dark side, his friends and brother will die. At first, Phineas says no, but then, he lies and says he needs to get a few things for his trip to the dark side. Instead he gets the help of his sister, the fireside girls, Yoda, who stowed away on the Executor, and Ferb, who escaped in ways I can't tell you at the moment. thumb|300px|right|Perry The Skywalker
Meanwhile, Dr. Doofenshmirtz has teamed up with Darth Vader, but only to later double cross him and take his spot next to the Emperor. He created the 'Force Draining-inator" so he can accomplish this. It takes the force capibilites out of a force sensetive and implants them into a non force sensitive.
Once the Emperor arrives on the Executor's bridge, Phineas, Ferb, Isabella, Perry, and everyone else begin to attack. They reveal that the Isabella, Perry, Buford, and Baljeet that Vader captured were all decoys (that's how Ferb escaped). The only one who doesn't get it is Dr. D, who was too busy setting up his machine, which looks a lot like his "Hot dog Vender Revenge-Inator" while Phineas and his friends are attacking Vader and Palpatine, Perry attacks Doof, who finally sees the decoys. They fight with lightsabers that they found lying around. After a few minutes, Phineas and his friends win the battle, but leave the Emperor and Vader alive, only unconcience. Then they all go home, and desrtoy the machine that started all this. After that, the boys sit down to a nice movie called Godzilla.
"Too Young Line"
Vader: Aren't you a little young to be a sith lord?
Phineas: No, because i'm not turning to the dark side!
Ferb: Is there even a chance we can win this battle
Yoda: if belive that we can win, you do, then win we will.