Sir Arthur Eddington is a renowned physicist at Cambridge University and an expert in the measurement of the physical world. He along with all of his colleagues are also avowed Newtonians. Sir Oliver Lodge suggests that he read a new thesis put forward by a German-Swiss scientist named Albert Einstein who is suggesting that Sir Isaac Newton may have got it wrong. The expectation is that Einstein's theories will be disproven but Eddington admits that his General Theory of Relativity has merit. These are turbulent times as England and Germany are at war and Eddington's own loyalty is called into question when, as a Quaker, he refuses to fight. In the end, Eddington develops a series of tests to either prove or disprove Einstein's theories. For his part, Einstein has his own struggles during this period: the breakdown of his marriage, his integration into the university in Berlin and his own strident pacifism that led him to oppose German militarism and the First World War...