While investigating a suspicious death in a prison, Nikki focuses her attention on the victim’s cellmate, a dangerous criminal from her past.

As the team investigate a second death, Nikki’s theory starts to fall apart. Can she put her fixation with Scott aside and find the killer?

In the first case for new recruit Adam, the murder of a swimming instructor leads the team to suspect her ex-boyfriend, a former cop. Meanwhile, Jack has an unexpected visitor.

Having traced Laura’s last movements to a suburban house, the team work to identify the bodies buried in the garden. Meanwhile, Jack must choose between his brother and the truth.

Nikki, Jack and Adam investigate the murder of a surgeon in a hospital. DNA evidence appears to implicate a patient who was under anaesthetic at the time of the killing.

With their suspect in a coma and an attacker seemingly at large in the hospital, Nikki calls on Adam’s expertise to help solve the case.

The murder of a promising boxer draws Nikki and Jack into the world of underground boxing. Meanwhile, Jack's brother Ryan is released from prison.

Jack, Nikki and Simone investigate another death connected to the underground boxing ring. Jack's loyalty is tested when he fears Ryan has put Cara in danger.

Nikki’s students make an alarming discovery while dissecting a body donated for their training. Jack and Simone try to save care home residents from a flood.

Stranded in the flooded care home, Jack and Simone fight to keep the residents alive - but Nikki discovers that they may be trapped inside with the killer.

Sam Ryan recruits the Lyell team to investigate the assassination of the health secretary, but Nikki is unsure whether Sam knows more than she's letting on.

DNA evidence linked to the health secretary’s assassination forces Nikki to face her past in the present. As her investigation progresses, Nikki realises that its consequences will affect her, and her profession, forever.

When a woman confesses to murdering her husband, the Lyell team must determine if all is as it seems. Meanwhile, Simone is shocked to be reunited with a detective from her childhood and struggles to untangle her past.

A secret from his father propels Jack to Belfast. Meanwhile, Simone and Nikki investigate the mystery of a burned body. As familial secrets come to the surface, Jack faces tragedy head on.

The death of an investigative journalist throws the spotlight on to Sam Ryan. Nikki begins to realise that the implications of her discoveries will challenge the principles of forensic science.

Events lead Nikki to conclude that getting the truth will put the Lyell team and everything they love in danger.

When a man plummets from a high-rise building, the Lyell team cross paths with the NCA and a notorious mafia group, pushing Nikki to make a tough decision.

Nikki becomes even more involved with the Ndrangheta mafia-group and Jack uncovers some disturbing leads. An unlikely alliance leads Nikki closer to the truth, but not without some collateral damage.

A lorry is found with people locked inside, some dead. With the survivors refusing to speak, Nikki and the team must use their pathological and forensic skills to identify them.

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.

Levelling-up leaders and environmental activists clash in a small town trying to look to the future. With a sabotaged train and a dead mayor, the activists become suspects.

The Lyell team return to the tunnel and uncover some difficult truths, while the police raid the protester camp, desperate for answers. Family ties are pushed to their limits.

Jack comes to the aid of an old friend, and is sucked into a difficult case, where he is pitted against his former mentor. As Nikki and the team start to create a picture of what happened, they learn nothing is as it seems. Dealing with a family of serving police officers, they have to tread carefully, as their relationships prove to be another obstacle for the team to overcome.

As they get to the heart of their investigation, the Lyell team navigate corruption, loss and deceit within the local police force, who have become a law unto themselves.

A new murder victim forces the team to consider whether a notorious serial killer has resurfaced after 20 years, or if they are dealing with a copycat.

When a woman’s body is removed from a reservoir, Nikki performs the post-mortem and confirms she is the deceased wife of pathologist Charles Beck. Jack and Velvy discover new evidence that leads to a surprising arrest as Nikki continues to seek the truth about notorious serial killer Calvin Dunn.

The team work a suspected suicide but the investigation raises more questions than it answers. Gabriel has an exciting new opportunity, both professionally and personally, and enlists Jack’s help. When a disgruntled professor of criminology is passed over for promotion, events take a truly sinister turn and the interview panel begin to be targeted. Could a member of the Lyell be next?

Events continue to spiral at the university and Cara becomes collateral damage. The riddle of the body in the Thames is solved. A breakthrough in the Cherry case is received from an unlikely source, but will the team get there before it is too late?

The team investigate the body of a woman found in a flat after being dead for a year. As they seek to find out the truth of her identity and what happened to her, they must draw on all of their forensic and pathology knowledge to solve the case. Even if the world had forgotten her, the Lyell are determined that she must get justice.

Nikki and Jack work to uncover the truth surrounding Roy’s death and consider if it’s linked to their original body. Meanwhile, D.I. Torres searches for a stalker and Cara is shocked at Velvy’s living conditions. As the case comes to a head, there are surprises afoot for the team.

The team investigate the death of a Burmese man on a deserted beach, as his young pregnant wife desperately hopes he is still alive. Nikki and Jack piece together the perplexing crime scene and find it poses more questions than it answers.

Nikki makes a breakthrough but can the team believe everything they are told? The Lyell is compromised in an unexpected way, as the team strive to find out who the man on the beach was and why he was killed. In a dark and chilling story, they must unite to discover the truth, and above all, trust no one.

The Lyell are called to a museum outside King’s Cross Station, where they discover the bodies of eight victims entombed below. With the knowledge that a prolific serial killer was operating in London nearly twenty years ago, Nikki and the team know this will be a case like no other.

Nikki continues to try and identify the last of the remaining bodies in an effort to uncover any connections and find motive, while Jack and the police begin to look into several two-decade old missing persons cases which might reveal the identity of the man dubbed “The King’s Cross Serial Killer”.

The death of an elderly woman found in a cave has the Lyell team asking what drives a person to murder someone so vulnerable. A new boss at the Lyell riles Jack.

Benjamin continues his desperate search for Gloria. Nikki’s disturbing discovery joins the dots. A new team member joins the Lyell.

When a man is found bludgeoned by a hammer, the Lyell are drawn deep into a conspiracy involving local government.

After another hammer attack, the Lyell team start uncovering connections to a conspiracy involving local government.

Dismembered body parts take Nikki into the crumbling world of criminal justice. Can the Lyell team find a missing barrister before it’s too late?

Nikki conducts an unusual post-mortem, and a terrifying discovery disturbs the team. DNA evidence forces the Lyall to seek advice from an unexpected quarter.

When a mysterious contagion starts to spread on a flight from Mumbai, Dr Nikki Alexander faces a race against time - at 30,000 feet - to contain a deadly illness.

When more passengers become infected on the plane, Nikki and the Lyell team must work to uncover the truth and find a cure before it’s too late.

When six people are slaughtered by an unknown gunman, Nikki and Jack must work against the clock to find the shooter. Can they find him in time before he kills again?

The Lyell team investigate another gruesome murder, and the identity of the shooter at the restaurant leads to an unsettling discovery.