Adapted from the 80th novel of the same name written by Keigo Higashino on his 30th anniversary. The story originated from a homicide case, in which unidentified bodies were found in two different hot springs. Professor Aoki (Sho Sakurai), a chemistry expert, confirmed that the death was an accident, but police officer Nakaoka suspected that the young wife of one of the deceased planned the murder in order to defraud insurance money. At this time, Aoki met a young woman Yuanhua (Suzu Hirose) and his childhood sweetheart Kento (Souta Fukushi), followed by a series of unidentified supernatural phenomena. Is all this an accident? Or murder? How will the many mysteries be solved?