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. Local crime expert and author Graham Johnson helps Gary and Martin with their investigations.