The Man from St. Petersburg — Ken Follett

In 1914, Germany arms for war and the allies are preparing their defences. Both sides need Russia. The Earl of Walden and Winston Churchill plan a secret Russian alliance, but a man steals into England, intent on leaving his mark on history. Fate catches up with a beautiful woman, a young girl and a star-crossed lover, while the police close in on the man who might bring England to her knees.