On Christmas Eve, 1800, a cart full of gunpowder explodes along the route of First Consul Napoléon Bonaparte's carriage in the midst of a busy Paris street. The bomb narrowly misses Bonaparte but kills or maims dozens of bystanders. Chief Inspector Roch Miquel, a young man with a bright future and a beautiful mistress, must arrest the assassins before they strike again. But in a city of almost one million, and with Royalists and revolutionaries alike conspiring to overthrow Bonaparte, Roch's task is near impossible. As the line between friend and foe blurs and his own father faces the guillotine, Roch has no choice but to trust those most likely to betray him.