From the bestselling author of The Seven Deaths of Evelyn Hardcastle and The Devil and the Dark Water comes an inventive, high-concept murder mystery: an ingenious puzzle, an extraordinary backdrop and an audacious solution.

Solve the murder to save what's left of the world.

Beyond the island there is nothing: the world was destroyed by a fog that swept the planet, killing anyone it touched.

On the island it is idyllic: 122 villagers and three scientists living in peaceful harmony. The villagers are content to fish, farm and feast, to obey their nightly curfew, to do what they're told by the scientists.

Until, to the islanders' horror, one of their beloved scientists is found brutally stabbed to death. And then they learn that the murder has triggered a lowering of the island's security system, the only thing that is keeping the fog at bay. If the murder isn't solved within ninety-two hours, the fog will smother the island―and everyone on it.

But the security system has also wiped out everyone's memory of exactly what happened the night before—which means that someone on the island is a murderer―and they don't even know it.

Meanwhile, the clock is ticking.