It might be said that at heart, Band of Angels is a love story. But the course of love between Catherine Carreg and her childhood friend Deio is a convoluted, meandering one. Catherine and Deio grew up riding horses together in Wales in the 1850s. But when Catherine matures, her family puts a stop to her adventures with Deio, seeing it as improper for a young lady. After her mother dies in childbirth, Catherine feels lost and isolated.