Glasgow is a city divided. Cut in half by one lethal weapon – the blade. There are more scarred faces in Glasgow than anywhere else in Britain and in 2002 the World Health Organisation designated Glasgow the murder capital of Europe. Gary Kemp examines a brutal razor attack in the 1920s, to find out why the Rangers and Celtic supporter’s rivalry runs far deeper than football. Martin investigates another victim who is cut down in the city in 2010 – this time butchered with a sword after an argument escalates out of control. Gary and Martin investigate two Glasgow gangs, one old and one new, using two savage blade attacks that typify the city’s street violence.

Gary and Martin turn the spotlight on Liverpool and its life blood, the River Mersey. From the very beginning the docks determined the fortunes of this city. They have also allowed local criminals to play a part on the international stage, the most infamous being Curtis Warren, a leading figure in the Liverpool Mafia in the '90s. Warren is the only known criminal to make it onto The Times Rich List; his fortune amassed in the murky world of Britain’s £2billion a year cocaine business. But Liverpool gangs haven’t always been such high rollers. In the 19th Century the stakes were much smaller. Members of the Cornermen Gang kicked an innocent man to death for just a few pence. It was a crime so violent it caused public outrage and became a watershed in the war against gangs in Liverpool. The Kemps investigate two very different Liverpool gang crimes, a street robbery for a sixpence and an international drug smuggling ring worth over £40 million.

A knife attack leaves a teenage gang member fatally wounded on an Edwardian Manchester street. Around a century later, in another part of the city, a man is shot dead attending the wake of his friend – the victim of another gang murder. For over a hundred years Manchester has had a deep-rooted gang culture. In this episode Gary investigates the Scuttles – a gang that spread fear through the streets of Manchester over a hundred years ago. While Martin investigates the ruthless Gooch Gang who tortured and killed without a second thought. This violent gang was responsible for around two dozen cold-blooded murders and was active until only a few years ago.

Gary and Martin Kemp turn their attentions to Britain’s capital. London has always had criminals. The biggest city in Britain is like a magnet to those wanting to make a bob or two – even if that means taking the law into their own hands. Since the 1900’s as many as 70 gangs have fought it out on London streets. The Second World War put pay to many of them but there was one vicious East End gang that kept alive even up to the 1960’s though their origins went right back to the 19th century. Gary investigates the infamous Watney Streeters gang. A hundred years later a new wave of Asian immigrants had arrived in London. To protect themselves they formed gangs but it wasn’t long before protection turned instead to extortion and then massive drug smuggling. Martin looks into the ruthless and dreaded Toot Nung gang from Southall, West London.