Yajima, a man who has just gotten out of prison, pays Shinjurou a visit. It turns out that he`s an old friend of Kaishou and he asks the young detective to break a secret code. Folded inside of a purloined book from Kaishou`s library is a piece of paper from Yajima`s own personalized manuscript paper with a series of numbers written on it. The decoded message indicates a planned rendezvous, which leads to the suspicion that Kaishou and Yajima`s wife had an affair while Yajima was incarcerated. But where are the Yajima children, who suddenly disappeared one day?