Fifteen years ago: A teenage girl is viciously assaulted as she picks flowers in a field on a midsummer's night. The crime is never reported. Present day: An unidentified man is killed in a hit-and-run. He is never reported missing. Across the city, a priest and his wife are found dead in an apparent double suicide. Assigned to investigate, Fredrika Bergman and her colleagues discover that a sinister evil links these seemingly unrelated events.