The last representatives of an aristocratic family live in the old English estate of Bookshaw - the eccentric Colonel de Luce and his three daughters. While the colonel is feverishly looking for ways to save the family from ruin, selling a collection of stamps and family silverware, the two eldest daughters, Ophelia and Daphne, play with the youngest in the Inquisition, but Flavia is not up to games, the young detective is busy with another investigation.