1900, Eilean Mòr: A trio of Lighthouse Keepers go missing . . .When Joseph Moore arrives as a relief keeper, he's troubled that the light isn't burning, that the keepers didn't meet him at the landing. After going ashore, he finds many troubling things . . . Not only are the keepers gone, but the doors are shut and locked, their cold weather gear was left behind, and all the clocks have stopped. Moore, along with three seamen, stay to keep the light going.But they aren't alone on the island . . .