Jamie Buchan, formerly a Queen's Scholar of Westminster School and now an undergraduate at the University of Edinburgh, has always been interested by the mathematical and cultural significance of numbers. He is a great-grandson of the writer and statesman John Buchan (first Lord Tweedsmuir), whose definitive thrillers, among them The Thirty-Nine Steps and Greenmantle, have been bestsellers for many years; The Thirty-Nine Steps has been filmed three times – memorably by Alfred Hitchcock in 1935, with Robert Donat and Madeleine Carroll. A nephew of the highly regarded novelist James Buchan and the gardening writer and journalist Ursula Buchan, he is also related to the bestselling novelist Elizabeth Buchan. In short, books are in his blood, although he makes no claim for his own writing as against the works of his distinguished relations. This, his first book, shows that numbers are also in his blood; not only did John Buchan write The Thirty-Nine Steps, but among his other novels are The Three Hostages and The House of the Four Winds.