A break-in at a sugar merchant's Mayfair home brings the Bow Street Runners into conflict with their patron, Lord Newcastle. He reminds the Fielding brothers that their prime duty is to protect the property of the rich and yet the number of burglaries has increased under their new police force. Determined to prove him wrong, the brothers search for the Irish suspects in the shanty towns of Covent Garden, known as the Seven Dials.