The night covers the gloomy alleys with darkness and only a few corners are still illuminated by the gaslights. Eight investigators have gathered to catch the cunning Jack the Ripper. But Jack is in fact cleverly impersonating one of them. In Mr. Jack, one of the players must help the investigators. By moving each character into light or shadow, the detective player makes successive deductions to uncover which investigator is in fact Jack, then he/she must try to catch the infamous ripper. The opponent, playing Jack, must do his best to delay the investigation. He can even try to use the darkness to secretly flee the district! A thrilling game for two players!