Detective Conan: Series 13 (2004)

Shinichi's mother, Yukiko Kudo, aids Ran's mother, Eri Kisaki, Ran and Conan in picking up the slack of an indebted Kogoro's investigation of a series of death threats made against a wealthy family patriarch...Following a lead to the Black Organization, Agasa, Conan and Haibara go to a design studio which belonged to her father and find themselves investigating a murder when the chief designer is poisoned...The Detective Boys help the police catch a notorious knife man when Ayumi becomes a witness to an attack and the key to the mystery lies in a strange S-like mark the perpetrator leaves behind...