Officers are called to a Grimsby pub when two visiting businessmen are left with serious facial injuries after being assaulted on a work night out, but the situation soon escalates when a large crowd of bystanders violently intervene as the police try to make an arrest. The main culprit is identified and arrested, but claims self-defence, while two others are taken in for their part in attacking police in the street disturbance. Humberside detectives have to try to separate the truth from the lies, hoping CCTV footage can help them challenge the suspects' version of events