Ceit Robertson, age ten, is the next Matrarc to the Society, a cultish matriarchal group living in an inconspicuous cul-de-sac in Venice Beach. When Ceit's mother is attacked by spirits from the old world, a failed exorcism results in Ceit's exile into the foster-care system in Los Angeles. She eventually lands in the infamous MacLaren Hall, a very real and historically auspicious center for disturbed and abandoned children in El Monte. As Ceit grows into a force of nature, she discovers that the devil might not be what we should truly fear. A sympathetic story of the devil in Los Angeles, Diabhal explores the true nature of evil and how intention colors our definition of what wickedness truly is.