Omar and his younger brother, Hassan, have spent most of their lives in Dadaab, a refugee camp in Kenya. Life is hard there: never enough food, achingly dull, and without access to the medical care Omar knows his nonverbal brother needs. So when Omar has the opportunity to go to school, he knows it might be a chance to change their future . . . but it would also mean leaving his brother, the only family member he has left, every day. Heartbreak, hope,...