It was a normal day when Phineas and Ferb were wondering what to do and they remember it's Christmas Eve and tomorrow Christmas so they invite Isabella over have fun on Christmas Eve by make a portal to allow them to bring people from another T.V. show which they happened to pick Avatar the last airbender and the Avatar the last airbender cast comes out of the portal and then they see it's 10:00 at night [it takes a long time to grab people from another T.V. show] and then when Phineas and Ferb wake up they see the Avatar the last airbender cast but little do they know when they got to Danville on Christmas Eve Azula came to also so they find a note but Aang and Zuko are the first one to notice it.