London, 1849. As a cholera epidemic draws nearer, 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 vision of a reborn London freed of rotting sewers. Then his beautiful young wife Isobella disappears and Joshua must turn his attention to even more perplexing matters. His search for the answers to the mysteries that surround him leads from glittering Haymarket cafes to London's murky underworld. What he finds will shatter his ideals and strike at the core of everything he has ever held dear.