There are times when people change the course of their history. It happens rarely and requires the union of many different wishes. This novel by Arantzazu Ametzaga tells passionately one of those chapters, perhaps the most important and unknown, which took place in a Pyrenean gorge back in August of 778. She tells the story in a documented and entertaining way, bringing together different stories from two timelines: the VIIIth century, going with Charlemagne to Vasconia, and the XIIIth century, developing stained glass in the cathedral of Chartres. A captivating tale to recall the deed which founded the first Vascones Kingdom.