The critically acclaimed documentary series returns with a new approach to serious crime as it follows the investigations of Bedfordshire Police around the clock. Police are called to investigate frantic banging coming from inside a refrigerated HGV lorry that recently passed through Dover after crossing the Channel. Inside, they discover a distressed three-year-old girl and her five-year-old sister along with their mother and 12 other migrants who have been smuggled into the UK. Bedfordshire Police now face a race against the clock to find out whether they have been illegally trafficked into the UK and deliberately imprisoned in the refrigerated container for more than 17 hours, or whether they have smuggled themselves aboard the lorry unbeknown to the driver and transport company. With the migrant crisis dominating the news agenda, this is real life drama at its most intense.