Charlie St. Cloud survives a car accident that takes the life of his younger brother, Sam. Before the accident, Charlie made a promise to Sam to practice baseball with him everyday until he leaves for college. After the funeral, Charlie is able to see the ghost of his brother, who reminds him of the promise.
Charlie meets a girl, Tess, and develops a relationship with her. As he becomes closer with Tess, he realizes that he is growing farther away from his brother. Charlie is torn between honoring his promise or moving forward with his newfound love.