Phineas and Ferb are at the museum for the day. Doofenshmirtz accidently fires his Revive-inator at a dinosaur skeleton and Phineas and Ferb must stop it. Meanwhile, Doofenshmirtz's daughter Vanessa is accidently transformed into a little girl, and Heinz must take care of her while trying to take over the Tri-State Area with an army of zombies.