A high school girl that has been missing for several years is found dead. Detective Utsumi of the Police Investigation Unit identifies the primary suspect as a man previously acquitted of murdering a young girl in a case led by Professor Yukawa`s best friend, senior detective Kusanagi. Once again, the suspect maintains his silence and is released due to insufficient evidence. To exacerbate matters, he returns to the high school girl`s hometown, creating an air of unease among its residents. And on the day of the summer festival parade, another incident occurs, presenting yet another challenging case for Yukawa, Utsumi and Kusanagi! A new "Galileo" mystery begins!