Richard (Mouri Kogoro) is playing Mahjong when they called a Loan Company President to play with them. When they find him in his office, he has died from Cyanide poisoning. The suspects are three of his employees. The poison was only found on the victim's thumb, money, and door handle, but nowhere else in the office. Conan solves the mystery, showing how Cyanide was erased with Bleach. The culprit explains how it was for revenge for putting the person's loved one in such a great debt.