On a rainy afternoon, the Detective Boys witness a murder across the street. Barred by traffic, the culprit slips away and Conan Edogawa is left a single clue by a dying detective. Days later, another detective is found murdered in a parking lot, leaving the police rattled. Suspicious that the culprit is one of their own, everyone in the police department without an alibi is suspect. But despite being on high alert, they are outmaneuvered and suffer yet another attack—this time with Ran Mouri finding herself in the crossfire.