On the surface, The Wave Theory of Angels offers two parallel stories of young women who fall into comas, and how their respective worlds attach meaning to a seemingly random event. Their collapse also coincides with calamity, suggesting that they are harbingers of doom.
The first story is about Christina, the 20-year-old daughter of a Beauvais stone carver who falls into unconsciousness in 1284 and wakes up just as the cathedral of St Pierre collapses. The second Christina, daughter of quantum physicist Giles Carver, lapses into coma in Chicago. Her waking seems to presage the collapse of that modern cathedral, the Twin Towers.
Although the characters make no explicit connection between these events, Giles's theory of waves that can collapse time suggests a possible relationship. He believes that the physical world consists of two 10-dimensional universes that communicate with each other by gravity. In the real world, his magic cannot prevent his wife from dying of cancer, or his other daughter Marguerite's sense of alienation, or Christina's retreat from reality. She awakes from the coma with a "misidentification syndrome", so that she can't recognise her father or sister. Only in the dark can she understand them as her family.
The Beauvais carver fares little better. His Christina twitches a foot just before she is lowered into her grave, and her miraculous recovery coincides with the fall of the cathedral. The father is blamed for this disaster so that he, a believer in radical metaphysics, is forced to leave Christina with the bishop for her own protection. His other daughter, Marguerite, rejects her father's position as religious outcast and throws away precious copies of philosophical works, deemed heretical.
The catalyst for change is a young man named Angel, an unseen stranger who travels across time to affect both families. His presence suggests that there is unfinished business in the medieval period, which he seeks to redress in the present. The four girls from two eras move as one in the world, each entangled in the others' lives.