'Some books set up house inside your soul. Utterly magnificent' - M. R. Carey

A remote island off the west coast of Ireland, St Brigid's, is a barren landscape, its small community dwindling. But, according to rumour, it is a magical place, a home to a healing well.

Rose and Emer have resisted the call to the mainland. They are sisters but opposites in every way. Rose, beautiful and blessed with a large family, dotes on the bitter and defiant Emer.

When a stranger arrives in search of a miracle, the islanders are determined to keep their secrets close. Little do they realise that the stranger's quest will endanger the lives of all who remain on the island.