In 1962, boxing writers and fans considered Cassius Clay an obnoxious self-promoter, and few believed that he would become the heavyweight champion of the world. But Malcolm X, the most famous minister in the Nation of Islam - a sect many white Americans deemed a hate cult - saw the potential in Clay, not just for boxing greatness, but as a means of spreading the Nation's message. Based on previously untapped sources, from Malcolm's personal papers to FBI records, 'Blood Brothers' offers an in-depth portrait of their complex bond.