In the ancient English manor of Букшоу the last representatives of aristocratic family dwell is an eccentric colonel de Люс and three his daughters. In summer of 1950 the viscous bog of rural life is violated by unbelievable events: murder of stranger and arrest of colonel. While senior daughters, as it should be to the well-mannered English ladies, sob in handkerchiefs, junior, eleven-year Флавия, in a delight: at last in her life something happened! Analytical constitution of mind, passion for chemistry and especially to poisons will help to understand this baffled business on that local policemen broke teeth her.Флавия proceeds to the searches that will bring her over neither anymore nor less than, as to king of England in person. In one she reposes: a father is not guilty - vice versa, he protects the daughters from something terrible.