When a man falls from a high-rise building, the Lyell team are drawn into the criminal underworld of notorious mafia-group, the 'Ndrangheta'. Aided by the National Crime Agency (NCA), Nikki and the team set out to uncover the truth. As they descend deeper into the murky depths of the investigation, Nikki soon finds herself embroiled further and further in the mafia's web.

Nikki is drawn further into the 'Ndrangheta mafia-group's twisted web and Jack uncovers some disturbing leads. An unlikely alliance leads Nikki closer to the truth but solving the crime carries deadly consequences.

An abandoned lorry is found at a quarry with several dead and dying people in the back. Initially, it appears to be a classic sex trafficking story that Nikki and the police are all too familiar with, but it soon becomes clear that all is not as it seems. With the survivors refusing to speak, Nikki and the team must use their pathological and forensic skills to identify the deceased and piece together what happened.

The Lyell team work together to find out why the lorry was found with bodies inside and a dead driver at the wheel, and are truly shocked to discover where it leads them. Gabriel becomes emotionally invested and is presented with an ethical dilemma, and Jack gets a surprise visit.

The Lyell team are thrown into the dark side of social media, where nothing is as it seems, and the perfect profiles of the influencers they are investigating raise disturbing questions. As a heavily pregnant DI asks the team for their expertise, are they running out of time to solve this case?

The investigation continues to take unexpected turns, with Nikki managing to get behind the mask of the lead suspect. Jack has a breakthrough at the festival site and Nikki takes a dangerous opportunity. A surprise event at the Lyell brings some hope.