Callum Hunt's life has fallen apart. His friend is gone. The spy has escaped. His secret is out. He is facing an existence behind bars, banished from the rest of the magical community for what he is - for what he might become. But a shocking revelation has promised freedom - at a cost. Will he stay strong, and faithful to his friends and teachers? Or take the risk, and destroy everything he's ever loved? This fourth year at the Magisterium will be unlike anything else that has gone before. 'I can't wait to read more of this series!' - Rick Riordan.