Captain Gabriel Lacey begins Spring 1818 preparing for a duel. But while he focuses on the affair of honor, darkness, greed, and death stalk the streets of London and bring tragedy to a family Lacey has grown close to.

With the aid of Lucius Grenville, London's most famous dandy, and Brewster, a ruffian employed by an underworld criminal, Lacey explores the world of molly houses and the double lives some men of society lead. His investigation takes him from the elegant mansions of Grosvenor Square to the squalid lanes of Seven Dials, to taverns that practice a highly illegal trade, spelling ruin and possible hanging for those caught within.

Lacey once again comes into the realm of James Denis, when what appears to be a simple crime of hatred becomes far more complex.