Lewis sinks deeper into trouble as his undercover operation spins out of control. Following a shoot-out with the East Street gang, he is ordered to act as courier when a hostage is exchanged for a gun the Skens are eager to get their hands on – and finds he is in danger from both sides. Back at the station, Mickey and Kezia work on a case in which explosives have gone missing from a contractor's depot. Roger voices his concern about his partner, but Heaton is too busy preparing for a sting where the Skens are due to buy explosives.