Hannah Snow and her husband, John, manage the lighthouse at Dangerfield, making sure that ships clear the treacherous Dangerfield coastline. One day, when John is out buying supplies, Hannah witnesses the Cynthia Rose crash into the craggy rocks, and she rushes out into the cold water. She is only able to save one sailor, Billy. Hannah soon learns that John will not be returning to her at the lighthouse and she falls into a deep depression, overcome with grief. Billy helps her maintain the lighthouse and continue to guard ships from the dangerous coast, but Hannah soon realizes that Billy is not who she thinks he is.