Since his assassination in 1968, Martin Luther King has become known and celebrated throughout the world as a champion of freedom. But there's another side to this man that's in danger of being forgotten - King the raging prophet of God's judgement on the West, the Baptist pastor who said that his mission was 'to redeem the soul of America'. Forty years after his death, politician and campaigner Oona King goes on a journey through the Deep South in search of this aspect of his leadership.