Meitantei Conan S15E38 - The Shadow of the Black Organization (The Mystery of the Big Reward)

Eisuke manages to find another case and convinces Kogoro into taking it. A woman is murdered, and her son says he saw who did it. Conan realizes that the case has something to do with the organization, as the boy was a witness to Kir's abduction by the FBI in episode 425.