In the fictional late-18th-century English city of Airenchester, Thaddeus Grainger, a young man of means but of meaningless pursuits, challenges his rival, Piers Massingham, to a duel over a young lady from the slums of The Steps. After suffering what he considers a cowardly cut at the hands of Massingham, Grainger vows revenge. When Massingham turns up dead a scant few hours later, Grainger is put on trial for murder. The young lady, Cassie Redruth, proud but poor, makes a brave attempt to defend him, but the young gentleman's fate is sealed. Cast into the notorious Bellstrom Gaol, Grainger must quickly learn to survive in the filthy, rotting prison, where debtors, gaolers, whores, thieves, and murderers mix freely and where every privilege comes at a price. Determined to exonerate their friend, Cassie and the journalist William Quillby must slowly piece together fragments of the mystery by infiltrating both the dregs and the gaudy upper classes of the town. To win Grainger's freedom, all three of them will be forced to confront grave dangers and uncover the ties connecting the "quality" of Airenchester with its teeming, violent, criminal underclass -- and come face to face with the one who controls it all. The Raven's Seal brings the urban squalor of 18th-century England vividly to life, while unravelling a tale of corruption, betrayal, murder, redemption, and love.