Sussex Academy is thrown into a panic when a mysterious monster is spotted in the toilets, the shower room, the kitchen and the sewer. When a large sea serpent is observed swimming in the nearby Reddington River, Shirley decides that the smaller critter must be a baby trapped somehow in the private school's pipes. She and her friends attempt to help the baby creature return to its mother before unscrupulous entrepreneurs can capture it and put it on display.
—David Bassler