While reporting to the chief that someone is getting the teenagers drunk, the Good Cops learn that they are under investigation by Internal Affairs, but even that won't stop them from uncovering 'The Russian Water Trick.'
Internal Affairs tests the mental and physical abilities of Sledge, Nicky and Perkins and then assigns a psychological evaluator to monitor their activities. The Good Cops show the evaluator what real detective work is, as they infiltrate the local High School.
After the death of Jean Deaux, a somber Sledge untangles his last words and uncovers a lead that could finally break open the case of the drunk teenagers, but it means they'll have to go undercover, deep undercover.
After Sledge and Perkins are imprisoned by Internal Affairs, Nicky has to pull out the "big guns" in order to set them free. Freedom however, does not stop Sledge from fighting through an internal crisis of conscience that leads to a most unwelcome visitor.