In 1990, three boys are born, unrelated but intertwined by circumstance: Dayo, Iseul, and Youssef. They are adopted as infants and live in a shared bedroom perched atop a mosque in one of Staten Island's most diverse and precarious neighborhoods, Coolidge. The three boys are an inseparable if conspicuous trio: Dayo is of Nigerian origin, Iseul is Korean, and Youssef indeterminately Middle Eastern. Nevertheless, Youssef is keeping a secret: he sees a hallucinatory double, an imaginary friend who seems absolutely real, a shapeshifting familiar he calls Brother. The boys' adoptive father, Imam Salim, is known for his radical sermons, but at home he is often absent, spending long evenings in his study with whiskey-laced coffee, writing letters to his former compatriots back in Saudi Arabia. Like Youssef, he too has secrets, including the cause of his failing health and the truth about what happened to the boys' parents.