The Hidden Antique Part 3

An antique art appraiser, Hogen Nishizu, is beaten to death with a spear and then stabbed to death. The police try to find someone who can appraise the black lacquer tray found at the scene but are unable to find him. While searching the house, the police find a box of small plates that Dr. Agasa had asked to be authenticated. According to the housekeeper's information, Nishizu had said, "I want to show this tsutsumi to the guests who come today and see their surprised faces when I explain it...