In Germany, Karl-Friedrich Bonhoeffer rose to prominence as a chemist, even as his relatives --Dietrich Bonhoeffer among them --became involved in resistance to Hitler, leading to their executions. This book traces the entanglement of science, religion, and politics in the Third Reich and in the lives of Karl-Friedrich, his family, and colleagues, including Fritz Haber and Werner Heisenberg. An expert on heavy water, a component of the atomic bomb, he collaborated with Paul Rosbaud, a scientific spy for the British known by the code name the Griffin.