The boys are helping Ferb's grandfather live his life long dream - to jump a gorge in his motorcycle, the Holy Mackerel. Meanwhile, Perry sets out to stop Dr. Doofenshmirtz from exacting another petty revenge that dates all the way back to the sandbox.

Phineas and Ferb help Baljeet build a portal to Mars for a special Summer science fair. Candace competes against another girl for getting a job at Mr. Slushy Burger. Meanwhile, Doofenshmitz builds a bicarbonate volcano for the science fair, in yet another attempt to redeem himself from his embarrassing childhood, where we discover where the -inator suffix originated from.