Anatolia, 260 AD. The siege of the Persians has worn down the resistance of the Roman city of Edessa. The emperor Publius Licinius Valerianus personally leads a delegation out of the city walls to make peace with his opponent, Shapur of Persia.
But no negotiations take place and no peace is sanctioned. The meeting is a trap, and Valerianus ends up in the hands of the enemy, along with the head of his personal guard, Marcus Metellus Aquila, legate of the Second Legion Augusta, a hero of the empire and a living legend for all Roman soldiers, and ten of his bravest and most and trustworthy men. Their fate is sealed and the shame of their capture forever engraved in bas-relief on the cliffs of Nasq-i-Rustam. They are left rot from forced labour, like the most miserable of wrongdoers, in a mine from which no one has ever escaped. The first to die of starvation is Valerianus, the others, guilty of having wanted to bestow honours worthy of the emperor of Rome, are buried in the bowels of the third level, a hell that knows no escape…