The genius Mitarai Kiyoshi (Tamaki Hiroshi) is a neuroscientist and famous sleuth. The author, Ishioka Kazuki (Domoto Koichi), is his good friend. One day, Ishioka starts to tell him about a mystery which he had heard on the radio. It is something that a listener had witnessed one day. A long-haired woman wearing a white dress was walking in the pouring rain with a closed umbrella. She held a small plastic bag in her hand and stood at a traffic intersection. However, the woman showed no sign of crossing the sidewalk even when the traffic light turned green. Just as the traffic light was about to change, she placed the folded umbrella on the road and hid in the shadows of a wall. Cars stayed clear, so she put it in the middle of the road. When a car finally ran over the umbrella, the woman picked up the bent umbrella and left in the rain. Ishioka is pleased to be able to share a story with an air of mystery that Mitarai seems to like. However, Mitarai figures out the woman’s mysterious behaviour in an instant and says with absolute certainty that a very bloody murder should have taken place near the place where this woman had walked. Despite the late hour, he contacts the police about the supposed murder in order to prove his own hypothesis. Then the next morning, the police receives a call from the first person to discover the dead body, just like Mitarai had hypothesised. Mitarai and Ishioka conduct an investigation of the crime scene together with the police. Like Mitarai’s hypothesis, the body of an old man who was stabbed to death, lies inside the apartment that is the crime scene. However, there is more. The dead body of a woman in a white dress, whom Mitarai regards as the murderer, is also in another room of the apartment … …