Saya Toma is a female detective with an IQ of 201. Takeru Sebumi is a career detective with a distinguished background. They work on cases by postulating the "SPEC" of the unknown criminals and then deduce the criminal's unknown "SPEC" to make arrests. A mystery occurs when bodies are found on a cruiser in the ocean. Saya Toma and Ryo Kase of the Tokyo Metropolitan Police Department are brought in to solve the case.

Set one year after the fight between detectives Saya Toma, Takeru Sebumi, and Satoshi Chii. More confrontations ensues between the detectives at the Unidentified Crimes Unit of the Tokyo Metropolitan Police Department. Takeru Sebumi returns after taking a break due to his eye problems. Kenzo Ichiyanagi is appointed section chief, while Kotaro Nonomura is demoted. New member Shu Kikkawa joins the team.