Cassidy Blake and her ghostly friend, Jacob, have survived the ghosts of Edinburgh and Paris, but New Orleans is a haunted city in a class by itself, and that is the current stop for her parents' TV show; but there is something a lot scarier than ghosts here: the Emissary of Death is after Cassidy, and to defeat it she will need the help of the Society of the Black Cat and she will also be faced with a terrible choice--lose one of her two friends,...

Now in Paris with her parents who are filming their TV show about the world's haunted cities, Cassidy Blake (who can see ghosts) and her friend Jacob (who is a ghost) are alert for trouble, especially when the filming takes them into the underground Catacombs, the empire of the dead, where Cassidy accidentally awakens a powerful poltergeist spirit--one whose mystery she must solve before his power in unleashed on the whole city.--