Phineas and Ferb: Thaddeus and Thor/De Plane! De Plane!

The Flynn's neighbors have relatives visiting who bear an uncanny resemblance to Candace, Phineas and Ferb. In fact, older sister Mandy has two younger brothers, Thaddeus and Thor, who drive her crazy with their ambitious projects. Although Candace and Mandy initially bond, they soon compete, urging their brothers to build the best backyard fort. Meanwhile, Perry finds himself in the middle of Dr. Doofenshmirtz's family reunion where Dr. Doofenshmirtz tries to throw the annual kickball tournament via the Kick-inator./ Phineas and Ferb set out to build a bigger plane than Howard Hughes' wooden 'Spruce Goose,' and to be environmentally conscious, they build it out of paper-mache, complete with in-flight service and entertainment. Dr. Doofenshmirtz is doing his part to be green by using recycled materials to build an "Evaporator-inator" to dry up all the pools in the Tri-State area. Meanwhile, Candace and Stacy attend Jeremy's pool party only to discover an adventurous Australian girl is capturing Jeremy's attention.