Six months after surviving Evershade Manor, scholar Edwin Blackthorn and mage Julian Thorne face a new horror: a killer turning victims to stone. Their investigation leads to Lucien Merrick, a brilliant alchemist obsessed with resurrecting his twin brother.

But as their partnership frays under the strain of past trauma, the hunt reverses. Merrick identifies Edwin's unique Fae blood as the final ingredient for his ritual, and the investigator becomes the captive. To save the man he secretly loves, Julian must trade his own freedom to a treacherous master from his past.

In a race against time, they must survive a collapsing laboratory, a public battle on Westminster Bridge, and the devastating truth of their own hearts. To save London, they must first save each other.