Is underground

The Children Of London Are Vanishing No one knows why, so Is Twite, younger sister of Dido Twite (from Dido and Pa and Nightbirds on Nantucket), sets out to discover the whereabouts of Arun, her cousin, and Davie, the king's only son -- both missing. Is soon finds herself aboard a secret midnight train heading north to Playland, a place of fun and frolic and dancing every night, or so they say.... Instead of fun, Is is heading straight into horrible, horrible danger...and exciting, terrifying adventure!