Detective Boone Drake has just masterminded the most massive sting in Chicago history, bringing down the heads of not only the biggest street gangs in the city but also the old crime syndicate. The story is the biggest in decades, and the Chicago Police Department must protect the key witness at all costs. Despite top-secret plans to transfer the witness ahead of his testimony before the grand jury, an attempt is made on his life. And the person suspected of leaking this information may be one of the CPD's own.