The Antique Tray Can't Be Hidden (3)

Appraiser Nishitsu Hogen is knocked to the ground and then stabbed to death with a spear. The police look for someone who can appraise the black lacquer trays at the crime scene but have trouble finding someone. While searching the house, the police find a box containing the dish Professor Agasa sought to have appraised. According to the housekeepers, Nishitsu said he was looking forward to seeing the surprised faces of the clients he had coming that day...