During the 1st century AD, a force of the Parthian Empire destroys a vexillation of a Roman auxiliary cohort sent to construct a fort on the banks of the Euphrates in the Kingdom of Palmyra.

Prefect Macro and Centurion Cato are drilling the Second Illyrian, an auxiliary cohort, attached to the Legio X Fretensis for the looming war.

Fearing the Parthians will arrive before the Romans can, Longinus sends the Second Illyrian and a cohort of the Legio X Fretensis to reinforce the loyalists.

The Romans and Balthus' men fight their way through to the city and manage to reinforce the loyalist troops, mainly composed of Greek mercenaries.

Following a banquet to celebrate the successful defence of a rebel assault, Amethus, one of Vabathus' sons is found murdered, with Balthus being the prime suspect.