Ian Brown's son, Walker, was born with a genetic mutation so rare that doctors call it an orphan syndrome: at most, three hundred people around the world live with it. At thirteen, Walker is still in diapers: he is globally delayed, he can't speak, and he has to wear cuffs on both arms so he won't constantly hit himself. He will require constant care for the rest of his life. The boy in the moon tells the story of one frail boy and the tiny constellation of people who love and care for him. From this intimate perspective, Ian Brown opens out a profound meditation on what life is worth, and what it means for all of us.