Christopher Tietjens, quietly preoccupied with his disastrous marriage to the beautiful, faithless Sylvia, takes a diverting golfing weekend in the country at the suggestion of his friend Macmaster. This is to change the course of the brilliant mathematician's life, for it is here he meets suffragette Valentine Wannop. Despite their mutual attraction and affection however, Tietjens refuses to betray Sylvia as she has betrayed him. With the coming of the War, the world of sureties and moral codes that Tietjens has known, believed in and upheld is shattered - as is he ...