A third and forth Batman killing was discovered. All four were experts in their fields: a race car driver, a demolitionist, a chemist, and a body builder. A fifth turned up, a gymnast. Gordon investigated by visiting a cross-bow expert (a cross-bow had killed the gymnast) who'd recently arrived in Gotham. He greeted Gordon in a Batman costume and told him that Bruce Wayne had sent it to him for a masquerade. The man died while Gordon was there. The Commissioner went to see Wayne. While talking to Wayne, Alfred brought in a package that had arrived - a Batman costume laced with acid.