Rebellion is in the air of London in the spring of 1663. Thomas Chaloner, spy for the King's intelligence service, has just returned from thwarting a planned revolt in Dublin, but soon realizes that England's capital is no haven of peace. He is ordered to investigate the shooting of a beggar during a royal procession. He soon learns the man is no vagrant, but someone with links to the powerful Company of Barber-Surgeons. His master, the Earl of Clarendon, is locked in a deadly feud with the Earl of Bristol, and an innocent man is about to be hanged in Newgate. Chaloner is embroiled in a desperate race against time to protect Clarendon, to discover the true identity of the beggar's murderer, and to save a blameless man from the executioner's noose.