The Lyell team investigate when a lorry is found in Kent with people locked inside. However, some have survived but will not speak to police. The team and the police delve into a world of drugs and human trafficking.
The team continue to try and find out information about the lorry of bodies with a dead driver at the wheel. Shocking leads shed some light on the case. An ethical dilemma grips Gabriel and there is a surprise visit.
The Lyell team are drawn into the dark side of social media when a man is found dead in a tent at a music festival. But with more twists coming and a heavily pregnant DI, can the case be solved?
The Lyell team return to the train tunnel and uncover some difficult truths. Meanwhile the police raid the protester camp, desperate for answers. Family ties are pushed to their limits.
Nikki and the team start to build a picture of what happened, but they doesn't get much out of it. Jack comes to the aid of an old friend and is sucked into a difficult case.