Candace is pleased that her mother wants to spend the whole day with her since this gives her a first hand view to bust Phineas and Ferb. But to her dismay, the boys only want to do dull, monotonous things. Perry discovers why due to the fact that the boys were hit by Doofenshmirtz's Dull-and-Boring-inator ray on his most recent mission. As a result, Agent P must return to D.E. Inc. so he can rebuild the device to reverse the ray's effect while Candace tries on her own to snap the boys out of their dullness.