"When Claire Cooper was eight years old her mother mysteriously vanished during Hop-tu-naa, Halloween on the Isle of Man. At fourteen, Claire is still struggling to come to terms with her disappearance when she's befriended by a group of five teenagers who mark every Halloween by performing dares. But Claire's arrival begins to alter the group's dynamic until one year a prank goes terribly wrong, changing all their futures and tearing the friends...