Matthias Fitzosbert is the illegitimate son of the parish priest of the village of Sutton Courteny. Despite the recent spate of murders, each day he braves the dark woods to visit his friend, a mysterious hermit who shows him many strange and beautiful things. Though enthralled, the boy is always puzzled by his lessons with the hermit - never more so than the night the villagers hunt the hermit down, and burn him, believing him to be responsible for the many deaths.

THE ROSE DEMON explores Matthias's unique relationship with a spirit he strives to placate but ultimately flees from. His story is played out against the vivid panorama of medieval life: the fall and sack of Constantinople; the turbulent Wars of the Roses; the terror of witchcraft; the battlefields of Spain and finally the lush jungles of the Caribbean where the Rose Demon and Matthias have one final, dramatic confrontation.