Edmund Blackstone, Bow Street Runner, of doubtful parentage and background, the best if far from the most conformist in the force, secretly applauds the robbers he hunts. He is tall, well-built, with a strongly featured face and, despite his elegant and expensive attire, moves with ease among the thieves and cut-throats in the taverns and soup shops, the cockfighting pits and dirty alleys of London. But if Blackstone has a weakness for professional esteem and flattery, for a woman's touch and for good wine, he is also one of the best shots in London, an expert in almost all areas of crime, a ruthless man with a reputation for courage and persistence, and - first and last - a Bow Street Runner. In this, the first of the series, Sir Richard Birnie, the Bow Street magistrate, has appointed Blackstone to guard the heir to the throne, the young Princess Alexandrina Victoria. Among the Runners this is considered an honour but Blackstone feels that it is all a waste of time, even a punishment. Then Blackstone himself is attacked outside his lodgings - and there's something about his assailant that seems oddly familiar...