The narrator and his brother Sonny have had a strained relationship for a long time. While Sonny was in high school (the narrator is 7 years older), the brothers lost their mother soon after losing their father. Sonny doesn't want to conform to his brother's wishes: staying in school in Harlem and following an employment plan. Instead, he is a musician and wants to become a jazz pianist. This mental divide, combined with the narrator's physical absence for a few years because of his military deployment, builds a wall between them.
One spring, well into their adulthood, the narrator reads in the paper that his brother has been arrested on heroin charges. He still doesn't reach out to his brother until tragedy strikes his own house. Grace, his beloved daughter, contracts polio; she suffers horribly and dies. In his own grief, the narrator begins to feel the pain of his brother.
He therefore writes the letter to his brother so that they can both find their way through the pain of their lives....
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