After the body of Otaro's former partner Kyujiro is found, Otaro is found dead in a locked room at the Hatobue Lodge. It becomes clear that Otaro was one of two culprits wearing Byun masks responsible for the robbery and murder that happened seven years ago. It also comes to light that Manager Yuri Asako's daughter Miona was the witness in the case. The police believe Otaro died in his room accidentally after killing Kyujiro to keep him quiet, but... While investigating Otaro's room, Conan closes in on the truth...
Conan inspecte le cadavre du prince de la bière, retrouvé dans sa chambre. Il comprend la vérité derrière le meurtre et celui d'il y a sept ans, et résout l'affaire.
La investigación continúa para averiguar la relación entre el asesinato de hace 7 años y los cometidos ahora.
警方开始调查啤酒王子南北家O太郎的死因，大家都有不在场证明，小五郎断言这是一场意外事故。但警方却从Q次郎的尸检报告中发现了疑点，经检查发现Q次郎尸体肺部里的水并不是池塘水而是自来水，而O太郎的房间里发现了监听器，上面还有Q次郎的指纹。更令人惊讶的是桌子上留下的指纹是O太郎的，而这指纹竟然与七年前抢劫杀人案犯人留下的指纹是一致的。
Conan intuisce che la povera ragazzina aveva assistito a un omicidio quando era piccola ed è rimasta traumatizzata. Durante le indagini si scopre anche che quasi tutti gli ospiti dell'albergo sono legati a quell'evento.
La investigació continua per esbrinar la relació entre l'assassinat de fa 7 anys i les comeses ara.
