Angela (age 10) and Ellie (age 6) live in Catskill, New York, a run-down town that business and industry have fled. Their mother, Mae, a beautiful, glamorous, eccentrically-dressed woman, has had to abandon her singing career because of an increasingly severe case of manic depression. Their father, Andrew, an earthy ex-musician, has made a pact not to put Mae on lithium; it kills her "spirit." In an effort to give the girls a "bland" experience to counteract the unpredictability of their lives, Andrew, himself an atheist, starts taking the family to church. He has no idea how powerfully the ideas embodied by Christianity will affect Angela, who becomes obsessed by the idea of sin. Angela convinces herself that the cleaner of sin she and her sister are, the happier their mother will be. To this end, she creates rituals to effect the inner purification of herself and her sister. Gradually, Angela moves further and further into the world of her own visionary imagination.