November, AD 370: Twenty-five years ago, as an old man lay dying in a cold city beside the Rhine, he told a five year old boy stories of the time, some sixty years earlier, when the rebel emperors Carausius and Allectus seized power in Northern Gaul and Britannia.

So why now, accused of bringing about the murder of a provincial governor by sorcery and under threat of execution, does Canio begin hearing the old man's voice in his dreams? Hearing again the same stories and remembering the things that his child's mind had long forgotten.

Past and present unfold in parallel - in wintry Londinium, across a stormy sea, in the warmth and bright sunlight of a May countryside, and finally back to a villa at the foot of the Long Limestone Hills.

And to a strange epiphany.