Feisty Sister Joan of the Order of the Daughters of Compassion returns to her convent in Cornwall from summer retreat in Scotland to be greeted by the news that the tiny school where she taught children of local farmers and resident gypsies will be disbanded. On a last sentimental visit there, she finds the strangled corpse of young Valerie Pendon, missing for several days. When a second young Catholic girl, similarly dressed in virginal white, turns up dead soon after, Sister Joan once again becomes an unofficial aid to Detective Sergeant Mill (A Vow of Chastity, 1992, etc.), whose force has been augmented by icy Sergeant David Barratt, newly arrived from Birmingham with his timid wife, Daisy. The threat of violence moves closer to the convent with sightings of a skulking figure, a warning message on an interior door, and an unconscious Sister Hilaria found outside the gates, victim of a hit-and-run driver. Aided by a few stray phrases and some heavy research, Sister Joan draws up her own near-fatal scenario for catching the murderer, to be saved by ever-commonsensical Mother Dorothy. A labored plot short on solid underpinning deflates the menace, but Sister Joan's admirers will find her new adventure modestly engrossing.