hogwarts organizes an overnight educational excursion, sending every student and professor across britain to explore ancient magical landmarks and strengthen unity between the houses. but when the convoy becomes stranded on a remote countryside road, an ancient winged predator, older than hogwarts itself, begins hunting them, ignoring ordinary magic and selecting its victims with terrifying purpose. cut off from help by powerful ancient magic, the students and professors must survive against a creature no one understands and no one knows how to kill.