On a sunny afternoon in late June , Cambridge don Joseph Reavley is summoned from a student cricket match to learn that his parents have died in a road accident. Joseph’s brother, Matthew, who is an officer in the Intelligence Service, reveals that their father had been en route to London to turn over to him a secret document allegedly with the power to dishonour England and damage the British Empire. At the same time, events in Sarajevo will propel Europe, and the whole world, into war. But there are some tragic deaths on the home front and where is this mysterious document…if it exists at all?