It's December and Christmas is coming, but Caroline Malloy and Wally Hatford aren't singing carols around the tree. Instead these sworn enemies must interview each other for the dreaded December class project. Caroline, as usual, has a trick up her sleeve that's sure to shock Wally in front of the entire class. That's just the first step in her gross-out Wally plan.

In the meantime, Wally and his brothers find a way to spy on the Malloy girls at home. The girls vow to get revenge on those sneaky Hatfords with a trap the boys won't soon forget. To make matters worse, Caroline and Wally are really in for it when the gross-out gifts meant for each other end up in the most unexpected places.