For two years, Dispatches has followed an undercover police operation as it tracked a criminal gang trying to smuggle guns into Britain. The painstaking work of Lancashire's Serious and Organised Crime Unit culminated in the seizure of a vehicle in Dover containing drugs, weapons and ammunition, and led to the successful conviction of over 20 people involved in this international crime ring. Operation Greengage exposed the trade in illegal weapons in one northern town. In Gun Nation, Dispatches examines the shocking proliferation of guns on Britain's streets.