London, 1849. As an epidemic of cholera draws nearer to the capital Joshua Jeavons, engineer, is working on his great drain plan for the capital. When the deaths begin, he works even more furiously, driven by the bold vision of a London freed of rotting sewers, cleansed and reborn. Then his beautiful young wife Isobella suddenly disappears and Jeavons must turn his attention to new and even more perplexing matters. His search for the answers to the mysteries that surround him leads to glittering Haymarket cafes and to London's murky underworld. What he finds there, amid poverty, disease and death, will shatter his ideals and strike at the core of everything he has ever held dear.