The Tortoise in Asia. Tony Grey

least the decision is not certain to lead to disaster. It most probably won’t. The fighting qualities of the Roman soldier should compensate for the poorer choice, despite the cost of additional casualties. But that cannot salve the wound to his conscience for it’s beside the point. He’s disobeyed the cardinal imperative of Stoic philosophy – make the right moral choice without regard to the consequences. Where would there be support for what he’s just done? Not in the books he reads.

      The conference is over. He and Cassius leave the praetorium without speaking. As the general is turning to go to his tent, Marcus moves to say something. If only he can open up the possibility of going back, this time arguing on the same side. Perhaps they can promote Cassius’ compromise in attacking virtually immediately, with just a short delay so as to avoid open terrain. But no sound comes out; the hard lines on Cassius’ face prevent it. He’s offended the second in command. At least he can take comfort in the fact that it relates to the view he expressed, not the reason behind it. That, at least, hasn’t been disclosed and never needs to be.

      The portentous decision’s been made – alea iacta est – the die is cast. It’s observed by the Three Sisters who weave the fate of mortals. They alone can foretell who of the tens of thousands of Romans and Parthians soon to be embraced in battle will pass by Lethe’s doomfull spring and forget their former lives.

      Next day, in the early morning as the water birds come to drink, shouts of command shatter the peace along the banks of the river of civilization. Centurions put into action the decision to march east along the Road to find the elusive enemy, with Ariamnes navigating. The Romans would have left it if its Commander in Chief had followed Cassius’ advice.

      The Road is honoured that it’s been chosen to carry the grand army into battle – better than being left out of the drama; perhaps it foresees that what it’s to facilitate will lead to one of the most curious developments in its long life.