Catilina's Riddle — Steven Saylor

When Gordianus the Finder deserts the fierce intrigues of Rome for domesticity on an Etruscan farm, his brilliant patron, the orator Cicero, draws him back with a curious proposal: keep Catilina, Cicero's radical rival, under a watchful eye.

Reluctantly Gordianus complies--and soon, despite himself, becomes attracted by the notorious populist politician. Could Catilina really be conspiring against the Republic? Or are Cicero's accusations of Catilina's personal depravity and revolutionary plots no more than vicious lies? Yet when Gordianus discovers a headless corpse in his stables, he is suddenly swept into a mystery more dangerous than any he has ever known....