Her big sister bosses her around; her mom makes her dog-sit Mr. Boots, the family's well-dressed Chihuahua; and she's convinced a strange and squishy swamp creature that lives down at the lake is eating high school kids. When no one believes her, Arlie and her best friend, Ty (yes, he's a boy, and no, he's not her boyfriend), set out with Mr. Boots to stop the creature themselves -- because if they don't, half the school is going to end up as lakeside hors d'oeuvres!
