Caroline O’Donoghue. Walker US, $19.99 (400p) ISBN 978-1-5362-2881-6 Teenage Margo is en route to boarding school in Dublin when her otherwise empty train stops inside a tunnel, triggering a panic attack. When Margo recovers, she notices that the train’s trappings have changed and she’s been joined by passenger Moon, who has never heard of Ireland. Confused and terrified, Margo disembarks with Moon in New Davia—one of several worlds connected by a strictly regulated railroad.