The Curse of Deadman's Forest (Oracles of Delphi Keep #2) by Victoria Laurie
Since Ian Wigby and his sister, Theodosia, found the silver treasure box and the prophecy within it, their world has changed. There's no denying what they discovered in Morocco: a powerful evil is budding, and to defeat it, and save the world from darkness, six uniquely gifted children must be gathered.
According to prophecy, a trip through the magical portal near the castle will bring them to the third Oracle--a child with extraordinary powers to heal. But the very same prophecy foretells Ian's death should he venture through the portal again.
Everyone agrees: to risk Ian's life is too great a gamble. But when a terrible curse enters the keep, it becomes clear that there is no other choice.
If Ian and Theo stay in Dover, all will surely be lost, but to follow the prophecy, they will risk their lives and everything they have ever held dear.
Dog Gone Note: This book is in excellent condition