Young rap artist Fulla T Smith (guest star "Fab Five Freddy") is leaving a radio station after finishing an interview and debuting his latest hit song, when shots ring out in the lobby and he's killed. Detectives Logan (Chris Noth) and Wheeler (Julianne Nicholson) question the one witness found on the scene, Harry Williams, (guest star Sticky Fingaz) who reveals he's an undercover cop whose task force specializes in crimes within the rap world. Williams warns Logan and Wheeler to watch themselves, but when he starts helping them out, witnesses turn up dead. The detectives begin to wonder which side he is on.
A Park Avenue dentist's murder turns out to be connected to the death of one of his young patients. As detectives Goren and Eames look into both murders, they follow a trail of counterfeit and poisoned mouthwash from the streets of Harlem to the FDA and Wall Street.