Phineas and Ferb build super tree houses for themselves and Candace, but things get a little out of hand when a treehouse fight instigates. Meanwhile, Dr. Doofenshmirtz plans to ruin a ceremony in his brother's honor.

The boys stage a chariot race through the town's streets after learning about ancient Greece. Meanwhile, Dr. Doofenshmritz creates a giant robot named Norm to destroy Perry, once and for all.