In the winter of 1912, in one of the districts of the Pskov province, a bloody murder occurred, stunning in its cruelty and scale. The unknown villain did not spare not only the adult inhabitants of a wealthy house, but also young children. Investigator Konstantin Pavlovich Marshal undertook to unravel this case, but it is not so easy, because there is not a single living witness left. It seems that the strange girl who always appears in black knows something, but it’s impossible to get testimony from her: she is a blessed woman who has not spoken a word for a long time. But the young investigator does not give up... The novel is based on real events.