Locked away inside the fortified walls of Oxford's St Wilfred's College, surrounded by alchemists sworn to protect them, Taylor and Sacha are safe from the Darkness. For now. But time is short. In seven days Sacha will turn 18, and the ancient curse that once made him invincible will kill him, unleashing unimaginable demonic horror upon the world. There is one way to stop it. Taylor and Sacha must go to where the curse was first cast - the medieval French city of Carcassonne - and face the demons. The journey will be dangerous. And monsters are waiting for them. But as Darkness descends on Oxford, their choice is stark. They must face everything that scares them, or lose everything they love.