In Sister Mary Helen's latest venture as an inadvertent detective, she must make do without her sidekick, Sister Eileen. So Mary Helen has no one with whom to share her fears when the head of St. Francis College dies suddenly and is replaced by the coldly efficient Sister Patricia. Mary Helen feels she will be swept aside as too old in the "clean sweep" that Sister Patricia is famous for in the order. To her rescue comes Sister Anne, who runs the Refuge, a shelter for homeless women. When a woman from the Refuge is found murdered in the alley, Sister Mary Helen goes to work searching for clues.