In the novel -- as in history -- Radegunda is the wife of Clotair, King of Gaul, seized by him as a prize of war. When she suspects Clotair of murdering her brother, she retreats from the blood-lust of the Dark Ages. Taking the young, innocent Agnes with her, she establishes a religious order where pain and denial are deemed the pathways to virtue and redemption. But the "calm" of self-renunciation cannot last when a sexual scandal involving Agnes is exposed. To expiate this sin, the "victim" fanatically decides to wall herself up. This decision sets off vicious rivalries among the women and draws Radegunda back to the kind of world she had escaped from.