Without telling the Sun Hill officers that PC Lewis Hardy has been working undercover with the Sken gang, Superintendent John Heaton and DCI Jack Meadows brief the team on the information they have been given by Lewis: the Skens are planning to ambush a cash van. At the Skens’ flat, Lewis pleads with Dominic Hardy not to be present for the robbery, due to take place the next day. Dominic angrily storms off while Lewis goes to meet Heaton and Jack to give them the details. Jack tells Lewis to encourage the gang to turn on the police radio they previously stole so the officers can locate them via GPS. When Lewis gets back to the house, he is shocked to learn that the robbery will be taking place that afternoon: he discreetly texts Jack to let him know that the robbery has been brought forward, but doesn’t have details of where it will take place. Lewis is confused when he is told to get on a motorbike with Tyrone and is driven to a courthouse. He soon realises that they are after a prisoner, not cash.Tyrone and Lewis follow the van into a tunnel, where the Skens have arranged an ambush. The Sun Hill officers are puzzled when the cash van drives through all the possible hold-up routes without any sign of trouble. Back at the prison van, Lewis is given a gun and told to get the driver out. The driver consents and releases Wayne – a Sken gang leader on trial for murdering a crack dealer. Heaton is soon notified that the GPS on the radio has been turned on and orders all units to the real location. When DC Mickey Webb tells Heaton that a prisoner transportation van is travelling along the same route, he realises with horror that it’s an escape taking place, not a robbery. As Lewis’ getaway car flies past Heaton, PCs Dan Casper and Will Fletcher give chase in their patrol car. Elsewhere, Jack hurries into a helicopter and trails the Skens car from above, notifying the officers that they are crossing Tower Bridge. Dan and Will race through the busy London streets but eventually lose sight of the Skens: Jack also loses visual contact when they drive into a tunnel.
Lewis and Dominic are taken to an apartment where the gang celebrate their victory. Wayne is deeply suspicious of Lewis and orders him not to move. Terrified, he and his cousin will be killed, Lewis whispers to Dominic that they should use the radio to send out a signal.
As it slowly dawns on Dominic that Lewis has been working undercover the whole time, he knows that they need to get out quickly. Pretending to make a drink, he presses the signal button, not realising that Wayne is watching him. The situation escalates and when gun shots are fired, Sun Hill CID and CO19 officers storm into the apartment the police catches the Skens except for one person - Tyrone. As Lewis and the police find Tyrone holding Dominic at gunpoint as Dominc escapes Tyrone shoots Lewis and the police shoot Tyrone and he is killed instantly. Lewis is rushed to the hospital as he comes round PC Roger comes to make a truce with him Lewis decides to permanently transfer to Operation Trident, in the hope of truly making a difference to the black community.