The adventures of summer beckon to The Stinkers, a group of mischievous misfits so named by Mr. Brinway, the weary headmaster of the Summer Program at upscale Dartmoor Academy. During a humdrum field trip to the Springville Aquarium, The Stinkers get the bright idea to kidnap Slappy the Sea Lion and return him to his ocean home. Unfortunately, there's another sea lion-napper on the premises, and he has other plans for Slappy's future... in a Bulgarian circus! The Stinkers manage to get Slappyback to Dartmoor only long enough for him to wreak havoc on Parent's Day and get the Stinkers expelled... leaving the poor sea lion in the hands of the evil animal broker! The Stinkers will have to pull out all the stops to save Slappy from circus life and redeem themselves in the eyes of Mr. Brinway!