In a small French town tragedy strikes. In turn killed three people, whose names were found previously written in chalk on the steps of a local funeral chapel. Young school teacher for boys, Marie Grande, discovers the night that one of the students, Antoine, sleepwalking. Marie keeps him in the company of the headmaster, Mr. Carolan. It turns out that Antoine goes to the cemetery and writes with chalk on the steps of the chapel of the name of another person who is soon to die. This person is about to be Mr. Carolan. Director tries to ignore the warning, but this time prophecy works. Terrified Marie, not believing that the director died of natural causes, calls for help Sherlock Holmes. Detective talking with school staff and the local doctor, Dr. Dimanche, asking him if the dead do not suffer any disease previously and the circumstances of their death. The doctor that did not find anything suspicious, it is suggested, however, that it has an unusual gift Antoine prediction woes. ...