Max Planck was Albert Einstein’s mentor, a bright light in physics often eclipsed by his star protégé. Brandon R. Brown’s account is written under the lens of World War II, with Planck driven from his home by Allied air raids and enduring the arrest of his son by the Gestapo. In flashbacks, Planck is shown pursuing physics in the late 19th century when science assured the world that there was nothing left to discover. Planck and the younger generation he inspired would soon prove them wrong. He fought many battles in his career against positivists who refused to believe in anything the senses couldn’t detect and Nazi scientists arguing against the “Jewish” theory of relativity. Although the writing is sometimes odd (one of Planck’s colleagues is described as “a bowling ball of mathematical physics talent”), Brown sketches a clear picture of his subject, a man whose conservative instincts didn’t preclude flights of imagination.