When a secret society tasked with protecting mythical creatures faces a threat from developers, a young boy named Col must navigate his mother's dangerous alliance with a shapeshifter to save the last Gorgon. Col struggles to protect his friend Connie from the machinations of the shapeshifter Kullervo, who seeks to exploit their connection for ultimate power. The narrative follows Col as he uncovers his mother's true intentions and the lethal nature of the Gorgon she guards. Set within the magical confines of Mallins Wood, the story forces the protagonist to distinguish between allies and enemies while facing the physical threat of a creature capable of killing with a single glance.

Readers frequently highlight the fast-paced nature of the narrative and the effective integration of mythological elements into a modern setting. Discussion often centers on the moral ambiguity of Col's mother and the tension created by her desperate choices. Critics note that the world-building successfully balances the whimsy of magical creatures with the darker implications of the antagonist's goals. The book is often praised for its ability to maintain suspense while exploring the complexities of friendship and loyalty under pressure.