Fox cousins Archie and Reddie are back, and their mission is to find Archie's favorite hat, which has mysteriously gone missing, so they can enjoy the Hat Day party with all their friends.

Dog and Hat are practically inseparable, and when the dots on Dog's favorite shirt disappear down a storm drain, the two friends descend into the sewers where they encounter many obstacles and unforeseen dangers--and come face-to-face with an alligator.

When Newell's very special hat is taken away at school, he and his most talented friends concoct the perfect plan to get it back.