They went in single file, as quietly as they could. The reeds rustled overhead, and they had wrapped cloths around their weapons, the ornaments on their belts and the horses’ tack to muffle them. Yet the squelch of mud and the slop of water, the creak of leather and rasp of laboured breathing were painfully loud. Barbad the old eunuch had a scarf around his mouth, but it did not totally muffle his persistent coughing. Once they put up a skein of geese. They took to the air honking with a clatter of wings. The men stood, hardly daring to breathe, covering the muzzles of the horses, willing them to make no sound. Valens felt something brush against his boot. In a moment it was gone. It took all his willpower not to cry out or leap away.

As the geese arrowed away low across the moon, Valens saw with dismay the first hint of the false dawn in the eastern sky. They had had but two hours to slip across the levee and vanish into the marshes north of the wall, and much of that precious time had elapsed.

No outcry followed the flight of the wild geese. Narses led them on through the endless fen.

A terrible doubt surfaced in Valens’s mind. Was the Persian lost? How could any man find his way through this damp desolation? The swaying banks of reeds all looked the same. The place would have changed out of all recognition since Narses hunted here. Were they wandering in circles? Even Hercules had been defeated by the marshes of Stymphalia and had had to shoot down its murderous inhabitants from dry ground.