The novel follows the life of a Rhode Island fisherman who is struggling to make ends meet and is determined to finish building his boat, Spartina. The protagonist is deeply connected to the sea and the coastal life, but is also frustrated by his poverty and the wealthy summer residents who seem to take over his town. His life becomes even more complicated when he starts an affair with a younger woman, further straining his relationship with his family. The story is a deep exploration of the protagonist's character, his struggles, and his relationship with the sea.

This novel explores the complex dynamics of a family dealing with a daughter's chronic illness. Born as a genetic match to help her older sister fight leukemia through countless surgeries, transfusions, and shots, the younger sibling starts to question her own autonomy and the life that has been chosen for her. As she seeks medical emancipation, the family is forced to confront ethical dilemmas, the bounds of parental love, and the meaning of sisterhood. The story unfolds through multiple perspectives, offering a deep dive into the emotional and moral complexities of using one child's body to save another's life, ultimately challenging the reader to ponder where sacrifices for loved ones should have their limits.