In 2009, while several high ranking officers die in accidents and the conclusions announced that they are accidents, Takeshi Ooyama questions the investigation. Then in 2021, a high-ranking member of the government died in the explosion of his limousine. Although the case is classified as an accident, the investigators Kento Saegusa and Misaki Sakurai have doubts about the conclusions of the investigation. Then, at 11:23 p.m., a walkie-talkie goes off, connecting Kento Saegusa and Takeshi Ooyama from 2009, the future and the past will work together to counter a bio-terrorist attack and solve their cases.