An apocalyptic novel about belief, religion, and the power of myth that blends the gripping, end-of-the-world storytelling of The Passage with the biting wit and epic queer romance that makes Natasha Pulley's books "delightful" (The Washington Post).

Jesuit priest Avelyn Brocken was born into a mining family in Hreodwater, a small, totally isolated salt town in the Fens of England. At age 16, he fled, abandoning his faith in the god of the mine—the Salt King—and the mythology that killed his whole family.

When a fellow priest is miraculously healed only to then be turned to salt after a visit to Hreodwater, Avelyn is sent by the Vatican to investigate. But in Hreodwater, the town's gentle doctor, Jericho, tells him that the priest is not the only one experiencing strange cures—and may not be the only one in danger from a substance in the mine that the locals call "salt light."

Avelyn and Jericho team up to protect the world from the salt light—but they may already be too late: strange happenings are occurring at mines all around the world. At an archaeological dig on the Dead Sea, electrical devices froth salt; at another salt mine in Russia, a KGB officer finds the bodies of five tourists who seem to have turned to salt; and at the huge salt works at Wieliczska in Poland, all communication is lost, and rumors circulate of total annihilation.

As salt light spreads, devastating cities around the world, Avelyn must decide what and who to believe—and whether his faith is strong enough to withstand an apocalypse.