The Swan was a very ancient inn, perhaps the most ancient of them all. It had been constructed in three parts: one was old, one was very old and one was older still. These different elements had been harmonized by the thatch that roofed them, the lichen that grew on the old stones and the ivy that scrambled up the walls ... in winter the drinkers were all locals, and they congregated in the winter room. It was a plain room in the oldest part of the inn, with a single window pierced through the thick stone wall. In daylight this window showed you Radcot Bridge and the river flowing through its three serene arches. By night (and this story begins at night) the bridge was drowned black, and it was only when your ears noticed the low and borderless sound of great quantities of moving water that you could make out the stretch of liquid blackness that flowed outside the window, shifting and undulating, darkly illuminated by some energy of its own making.