A man comes to Luton Police station claiming that his life's in danger and that he's just escaped from a slave-owning gang who have held him captive at a Travellers site in a remote part of Bedfordshire. The police are prioritising allegations of 'modern day slavery'. They launch a major operation to see if they can find evidence of his claims. Over 200 officers are drafted in to help launch a dawn raid on the site to arrest their suspects. Cameras follow every twist and turn of the investigation as the detectives work out if they can believe the allegations, and whether they can find the evidence to build a case. This is real-life drama at its most intense.