For readers of Karen Armstrong and Kathleen Norris comes a powerful, unforgettable spiritual autobiography. An Unquenchable Thirst is the story of Mary Johnson's twenty years as a Missionary of Charity -- working alongside Mother Teresa in service to the world's poor -- and a fascinating depiction of the daily struggle to live a life of religious service. At 17, Johnson experienced her calling when she saw a photo of Mother Teresa on the cover of Time. Eighteen months later she found herself in religious training in a South Bronx convent. This boisterous, independent-minded teenager adapted, eventually, to the austere life of poverty and devotion, but faced daily the struggles of any young woman -- the same desires for love and connection and meaning and identity. After 20 years, Johnson left the order and has since left the church, but the story of this complicated, extraordinary woman will speak to atheists and true believers alike.