Arden Beacon arrives in the salt-swept port of Vigil with a job to do. Tasked with using the magic in her blood to keep the lighthouse burning, she needs to prove herself worthy of her family name and her ancestors’ profession.

But the coastline Arden must keep alight – battered by a sea teeming with colossal, ancient beasts – is far from the cultured, urban world she knows. It is a place of secrets, rumours and tight-lipped expectations of a woman’s place. More than anyone, the town folk whisper about Arden’s neighbour, Jonah Riven, the hunter of leviathans. They say he murdered his wife. They say he is as much a monster as his prey.

Amidst all her determination and homesickness Arden cannot get this shadowy stranger out of her head. A plot swirls around the lighthouse keeper, the hunter and the authorities. Arden must make sense of these dark waters – before they wash her away.