Inside a Benedictine monastery on Egret Island, off the South Carolina coast, is a beautiful and mysterious chair ornately carved with mermaids and dedicated to a saint who, legend claims, was a mermaid before her conversion. It is to Egret Island that Jessie Sullivan, a woman whose life has been constrained by circumstances, to care for her mother, who hasn't yet recovered from Jessie's father's death 33 years before. As Jessie contemplates the separation between herself and her husband, she is attracted to Thomas, a Benedictine monk soon to take his final vows, even as she tries to learn why her mother is haunted by her father's death after so many years have passed.