This Italian/Spanish horror thriller walks us through the tale of Jack the Ripper once again. A nameless woman enters her room and begins to undress, only to be stabbed. Similar scenes are repeatedly shown. Suspicion for the crimes falls on a known knife-fighter in the Soho region of London. Scotland Yard headquarters erupts into a flurry of meetings and discussions. Some investigation eventually ensues but with little result, for the killings continue. Gradually, a police aide draws suspicion on himself, and his collection of gory souvenirs is discovered in his home. The Scotland Yard inspector on the scene is nearly killed, but he is saved by the Soho knifefighter.