The Prisoner's Dilemma by Sean Stuart O'Connor

the start point for all navigation, the prime meridian, will run through the home city of the person that solves the problem. And for Dunbeath that has to be Edinburgh. It would be where East meets West, where half the world shakes hands with the other. Where else should that be but Edinburgh, the greatest centre of learning of our age? He would rather die than see the honour go to London.’
    Smith laughed for the first time that evening.
    â€˜How very, very interesting. I look forward to hearing about your visit and Lord Dunbeath’s game. Perhaps you’d be kind enough to write to me while you’re there?’
    â€˜I most certainly shall,’ replied David Hume, raising his glass to his new friend. ‘You have my word on that.’

Chapter 4
    If the winter was harsh at the Castle of Beath this February, the thermometer was yet lower still, fifteen hundred nautical miles away in the south eastern Baltic, and it was there that the port of Königsberg lay huddled under a heavy blanket of snow.
    Snow, rain or fine, however, trade was the lifeblood of the great city and trade would flow through its veins whatever the heavens might bring. The port sat on the banks of the mighty River Pregel and this great waterway washed around the two islands that formed the centre of the city before it drained into the vastness of the Frisches Haff, the more westerly of the two lagoons that connected Königsberg to the coast. From this enormous lake, ships would pass through a narrow gap in the long sandy spits that enclosed the lagoon, and from there out into the Baltic. It was this extraordinary natural position that gave Königsberg the most blessed of its attributes for it ensured that the port was ice free all year round. Unsurprisingly the city fathers took full advantage of this, and as Prussia’s merchant elite, they made certain that the great trading centre was open for business at all times. Now, in this fierce winter, teams of men could be seen labouring around the clock to clear snow from the roads and lanes that led to the quays.
    The people of Königsberg were as proud of the city’s past greatness as they were of its current prosperity. For centuries it had been the capital of the monastic state of the Teutonic order, and although successive port masters had repeatedly modernised the warehouses and wharves that lined the riverbanks, the burghers themselves preferred to leave unchanged the extraordinary medieval heart of the city.
    Three men now walked away from the forest of masts at the main quay and headed towards this ancient centre. They made their way across the first of the famous seven bridges that connected the islands to the mainland, and from there ontowards the Great Square, their bodies hunched against the harsh north-easterly that blew down from the Gulf of Finland. Slowly they passed the baroque beauty of the Marienkirche, then crossed the square itself and turned with relief into the relative shelter of the warren of ancient streets beside the Rathaus, the magnificent City Hall.
    Two men flanked a far larger man that walked between them, padding along with a strangely deliberate tread, deep in thought. The outer two had the air of an escort although they wore the sailors’ standard clothing of a thick jacket and heavy sea boots. Like so many of their kind on the quayside, they rolled unevenly as they walked, clearly less certain of a street under their feet than a deck.
    But it was the central character that took the eye. Alexis Zweig. A sea captain.
    Not only was he taller than his companions but he was far more powerfully built. Unlike most men of such stature, however, he wore his scale with such a relaxed air that his physical presence seemed more latent than actual. If one had to guess at his age, he looked to be in his early thirties but he carried about him a far more timeless sense of authority. Now, in response to a tiny gesture of command from him, the little