«The Racing Factions» by Robert Fabbri

An ebook-exclusive short story from the bestselling Vespasian series.
Marcus Salvius Magnus is a fanatical supporter of the Green Racing Faction and expects a wager to be honoured. Although he does not presume honesty from anyone, he does believe that a bookmaker at the Circus Maximus should record each bet scrupulously and pay the full amount due. But Ignatius, the bookmaker, is foolish enough to attempt to cheat Magnus out of his winnings, incurring not only his wrath but that also of the South Quirinal Crossroads Brotherhood of which Magnus is the leader. In the shady realm of Rome's underworld Magnus will use the full resources of his criminal fraternity to exact appropriate vengeance.
But Magnus also has a problem: his patron, Gaius Vespasius Pollo, is attempting to get his nephew, Sabinus, elected as a quaestor. To do this he feels that the support of the senior consul, Gnaeus Domitius Ahenobarbus, would be more than useful. He asks Magnus to ease the consul – a man known for his extreme violence – in the right direction.
Ahenobarbus has a passion: the Red Faction at the circus. Could it be that Magnus might wash two tunics in the same tub, bringing Ignatius down and securing Ahenobarbus' support by attempting to fix a chariot race in a manner that has never been done before?