May 1959. From one side of St. Brigid’s Island, the mountains of Connemara are faintly visible on the distant mainland; from the other, the Atlantic stretches as far as the eye can see. This remote settlement, without electricity or even a harbor, has scarcely altered for centuries. Those who live there, including sisters Rose and Emer, are hardy and resourceful, dependent on the sea and each other for survival. Despite the island’s natural beauty, it is a place that people move away from, not to—until an outspoken American, also named Brigid, arrives to claim her late uncle’s cottage.
Brigid has come for more than an inheritance. She’s seeking a holy well that’s rumored to grant miracles, but the islanders won’t admit that it exists. Emer, as scarred and wary as Rose is beautiful and friendly, has good reason to believe in inexplicable powers. Despite her own strange abilities—or perhaps because of them—Emer fears that she won’t be able to save her young son, Niall, from a growing threat. As months pass and Brigid carves out a place on the island and in the sisters’ lives, a complicated web of betrayal, fear, and desire culminates in one shocking night that will change the island, and its inhabitants, forever.