Clara Bard s, granddaughter of a famous deceased painter, has been hired to restore a series of paintings, some dating from the Middle Ages, which are preserved in the Notre-Dame Cathedral in Paris. During a solitary visit to the upper part of the building, when the tourists have already left, she notices the deformed silhouette of Ergaster, a perverse torturer whom she believed to be dead and of whom she could have been another victim, along...