Yugami, feeling down about his favorite racehorse's retirement, takes Hanyu to a nightclub where they encounter a former thief, now trying to live an honest life. A few days later, she is found dead with a large sum of money, and her death is deemed an accident. However, Yugami suspects foul play due to her past skills and a promise she made to him. Meanwhile, the team is drawn into a fraud investigation targeting the elderly, where an unexpected connection to the woman’s death emerges.