Unholy Island, the mostly forgotten neighbor of Holy Island, is a strange place that everyone quickly forgets, except the few granted sanctuary there. Esme Gray escaped an abusive marriage and found her way to the island because their previous Ward Witch had died, and ridiculous as it seems, it's now her job to run the guesthouse while she maintains the island's protections. Luke Taylor has been searching over a year for his missing twin brother and follows a rumor that leads him to Unholy Island, where a suspicious murder leaves the island in need of a Book Keeper, which he finds a strange term for someone who runs a bookshop. Then there is the kindly old mayor Tobias who was the island's first resident so long ago he barely recalls his true nature. All three of them are weaker than they should be, but together they form a tenuous bulwark against the end of the Earth.