Kogoro is undercover at the Blue Parrot, because Yuzuki Fukui asked him to investigate on a weird sound she hears frequently. Conan joins him, saying that Ran is angry because Kogoro is not home. But a simple investigation in a bar becomes more dramatic when Chikafumi Usuda, an office worker, is found dead.

Ran has to open Waka's apartment with a key when no one answers. Later, Ran finds Waka on the bathroom floor, but she collapses herself due to chlorofoam in the air.