Story Time by Edward Bloor (2005)
Middle Grade Fiction | Horror-ThrillerBlurb:
“George and Kate are promised the finest education when they transfer to the Whittaker Magnet School. It boasts the highest test scores in the nation. But at what price? Their school’s curriculum is focused on beating standardized tests; classes are held in dreary, windowless rooms; and students are force-fed noxious protein shakes to improve their test performance. Worst of all, there seems to be a demon loose in the building, one whose murderous work has only just begun.