[1] Set in ancient Rome, the novel's central character and narrator is Marcus Didius Falco, informer and imperial agent.

The title refers to the Saturnalia feast held annually on 17 December, at which the Romans commemorated the dedication of the temple of the god Saturn.

As the festival meant for healing grudges riotously proceeds, a young man who has everything to live for dies a horrific death while the security of the Empire is compromised by the usual mixture of top brass incompetence, bureaucratic in-fighting and popular indifference.

But for the non-persons on the fringes of society life is not so jolly, and dark spirits walk abroad (available for hire through the usual agents).

Falco has a race against time to find a dangerous missing person, aided and hindered by faces from the past, while running the gauntlet of the best and worst Roman society can offer as Saturnalia entertainment.