5th century. Slowly but surely, a shadow extends over Gwenc'hlan, one of the last Druids, and his apprentice, Taran. Both continue their investigation into the mystery of the rocky promontories of Armorique. The needs of the investigation lead them to the sumptuous city of Is over which the beautiful and rebel Dahud reigns. It is in this place that the archanes of a vast plot will unravel.