Spies have reported the sighting of a Rat King in the Underland, a character who has been legendary since the Middle Ages. The Rat King is destined to bring a World War to the Underland. Gregorventually comes face to face with the Rat King, and to his surprise, he finds he is unable to kill this creature. Will it be a decision he lives to regret?
When eleven-year-old Gregor falls through a grate in the laundry room of his apartment building, he hurtles into the dark Underland, where spiders, rats and giant cockroaches coexist uneasily with humans. This world is on the brink of war, and Gregor's arrival is no accident.