Sally Tinker is the world's foremost inventor under the age of twelve, but her arch nemesis Dexter Maelstrom has long coveted the title. When Dexter invites Sally to view his latest invention, the extraordinary dinosaur creating devolving ray, things quickly deteriorate into an all-out battle of wits, wisdom and outsized chickens. when Dexter's chickensaurs break free and go on the hunt, Sally - along with her friend Charli and her baby brother Joe - must avoid becoming chicken feed. Is Dexter behind this dastardly plan - or is somebody else the bad egg?