Ruby and Marcus get entangled in a sibling battle for personal space during a class on undersea life. When Ruby stops to giggle over a fish which looks just like Earl, Earl gets so mad that he floods the school with giant hungry fish! A lonely only child, Earl also abhors siblings who can't get along, and enjoys plunging them into ""an ocean of space""! Drawing on a home economics lesson about cooking, the kids plunge underwater in a pressure cooker to unclog the drain (and drain out the school). But Marcus and Ruby are so caught up in sibling strife that they threaten to upset the pot's delicate balance. Only when the two siblings agree to respect each other's space and work together can the kids successfully open the drain and flood Earl's boiler room!