Jealousy From Overseas

One day in danville, Phineas & Ferb were doing.... well, nothing actually. But, they were thinking of doing something. They just didn't know what. So there they were, doing nothing but contemplating what to do, until.... *knock knock knock* I wonder who that is? Phineas said. As Phineas walked towards the door, the person knocked again, this time saying: "Hello, anybody home?" Phineas then opened the door to see.... nobody he'd ever seen before.