Milo and his friends crash a party thrown for the Mayor's daughter, Debbie Bledsoe, and they cause the Debbie's new locket to be tossed into the sewer. The zaftig Helga goes after the gift and gets lodged in the pipe, plugging it up like a human cork. The hill people and rescuers work feverishly to rescue... the locket, and leave Helga blocking the main water line -- just one flush away from the great beyond. Helga causes a disruption in the water supply to valley, but the hill people pay no attention -- until their water is cut off too.

Milo runs for school president against Debbie Klimer, leader of the snobby Debbies, and he loses -- but then his opponent suffers a freak accident. The Klimer family fakes young Debbie's death while she goes under the plastic surgeon's knife, but the operation is less than successful and Debbie returns looking like The Phantom of the Opera. Shunned by her upscale family and friends, The Oblong clan and the valley kids take in the reject Debbie as one of their own. But when Debbie's cheerfulness starts getting on everyone's nerves, the valley kids turn to the freakish school nurse to get Debbie back with the in-crowd.