The episode picks up where it left off, namely with the investigation into Sachiko's death in the hot springs of Benizome. Kamonohashi Ron, Isshiki Totomaru, and Detective Amamiya are the main figures in this case. Kamonohashi clears Amamiya as a suspect by pointing out that she couldn't have known about the hot spring's secret legend, which was only mentioned in a special brochure.

A guest mentions seeing a white mist near the river, prompting Kamonohashi and Totomaru to investigate. They discover that the mist is steam from hot water being diverted into the cold river. This clue leads them to Sachiko's husband as the culprit. He had manipulated the hot spring water to make it ice-cold, causing Sachiko to suffer a heat shock due to her pre-existing heart condition. Additionally, he tried to frame her death as the result of the hot spring's curse by using fallen leaves.

During the investigation, it is revealed that a mysterious man named Spitz Fire is the instructor of the detective school BLUE. He has been following Kamonohashi to determine whether he is still a detective. After being convinced of Kamonohashi's abilities, Spitz Fire asks him for help in finding his missing family. Kamonohashi hesitates at first but agrees after Totomaru vouches for Spitz Fire.

Spitz Fire offers to assist Kamonohashi in his detective work and even gifts him a happi coat. Kamonohashi remains skeptical but agrees to collaborate with Spitz Fire in the future, especially since Totomaru considers him trustworthy.

The episode ends with Kamonohashi contemplating whether to trust Spitz Fire and utilize his tracking skills for future cases.