The instant New York Times bestseller Trouble is haunting Cassidy Blake . . . even more than usual.She (plus her ghost best friend, Jacob, of course) is in Paris, where Cass's parents are filming their TV show about the world's most haunted cities. Sure, it's fun eating croissants and seeing the Eiffel Tower, but there's true ghostly danger lurking beneath Paris, in the creepy underground Catacombs.When Cass accidentally awakens a frighteningly strong spirit, she must rely on her still-growing skills as a ghosthunter -- and turn to friends both old and new to help her unravel a mystery. But time is running out, and the spirit is only growing stronger.And if Cass fails, the force she's unleashed could haunt the city forever.#1 New York Times bestselling author Victoria Schwab returns to the spooky and heart-pounding world of City of Ghosts, delivering thrilling new adventures and an unforgettable spin on friendship. (Because sometimes, even psychic ghost best friends have secrets . . .)