Professor Leo Dalton and Dr Harry Cunningham join Sam Ryan in the investigation of a massive traffic accident in which not everything is as it seems.

Sam, Leo and Harry are at odds with the police investigators when a covert operation is exposed. But has Sam overstepped the mark this time?

The police bring in the team when a family is attacked in their own home, leaving the only survivors in critical condition.

A new murder turns DCI Ashton's suspicions toward the victim's family and friends, whilst Harry investigates a death that may be linked to the Irons family.

Murder is suspected when the body of a missing person is found hidden within a derelict factory, seven years since he was last seen alive.

As Sam searches for the killer of Marcus Saul, Harry finds himself involved in the tragic death of a student from the medical faculty.

The murder of a probation officer leads the team to the doorstep of a police cadet college, as they quickly establish a link to a similar murder just months before.

As the police investigate the possibility of a copycat killer among the students, a friend from the college pressures Sam to put loyalty above the truth as the case unfolds.

Sam is called after a suspected terrorist attack causes a fire at a hotel and a government minister is injured.

Sam delves deeper into the case but is undermined by the findings of an independent pathologist, brought in to conduct a second autopsy.

Sam comes under scrutiny at an official inquiry into two prison deaths and an old case Sam worked on 13 years resurfaces.

Sam uncovers a crippling truth about her involvement in a 13-year-old case -did she help convict an innocent man?

The body of a young pregnant sports agent is found in the grounds of her office building. Sam and her team uncover a tragic story of money and corruption.

Following her discovery of the second body and believing the cases to be linked, Sam is sidelined from the investigation as she attempts to get to the truth.

The Home Office ask Sam and her team to examine a number of times of death as given by a highly respected and internationally renowned independent pathologist, Peter Sachs.

Leo and Harry follow up their leads to discover an alarming truth. Are Sam and her team being used by the Home Office to drive out Peter Sachs in fear of a costly process?

The bodies of two young men are discovered, partially exposed, following a landslide on the coast of Northern Ireland.

The case takes an interesting turn when the bodies are identified as brothers who disappeared after a police questioning during the Troubles.

Suspicious symptoms afflicting a group of children on the coast may be linked to the death of a local man.

Leo hunts for the source of the children's symptoms before any more fatalities occur. Meanwhile Harry discovers the truth behind Nick Garner's death.

The death of a jockey during a race becomes more complicated when the horse's owners are killed in a helicopter crash.

Foul play is confirmed when it emerges that both the horse and the helicopter pilot were drugged. Could syndicate member Matt Gibb be responsible?

Leo and his team are approached by a support group to help discover the truth behind a train crash.

Leo, Harry and Nikki step up their efforts to discover the truth behind the train crash but there are still many unanswered questions.

When his wife and teenage daughter are involved in a hit-and-run car crash, Leo begins a painful journey back to his native Sheffield.

As the police infiltrate a gang of identity thieves, Leo faces a choice between justice and revenge.

The team is called to a drive-by shooting outside a London nightclub. They arrive to a scene of carnage with several people dead, or dying.

The man behind the bloodshed pits both factions against one another and the team are in a race against time.

The team is drawn into the investigation of a series of brutal, apparently motiveless murders in the academic world.

Nikki's beliefs are put to the test as she realises they are facing murders that are committed for sheer pleasure.

A paranoid schizophrenic goes on a violent frenzy in a busy high street. When a young man from the same care home commits suicide, Nikki is convinced there is a connection.

Harry discovers Nazim's death may not have been suicide. Is Dr Sanders the culprit? Meanwhile Leo investigates the murder of a bank manager.

When a boat carrying illegal passengers is found crashed in the Thames, the team investigate.

The team follows the trail of the people traffickers, and has to find any remaining survivors before a highly contagious disease breaks.

The team investigates a hit-and-run accident, an arson and a woman who collapsed on her hen night.

The team investigate a man who died on a night bus, an office prank gone tragically wrong and the suicide of a pro footballer.

Harry and Nikki's friendship is rocked by the discovery of the body of Harry's ex-lover.

Memories of his own daughter's death are stirred up when Leo is called in to investigate the suicide of a 14-year-old girl.

Memories of his own daughter's death are stirred up when Leo is called in to investigate the apparent suicide of a teenage girl.

When a third killing takes place on school grounds, Leo races to find some connection between the apparently motiveless murders.

Harry and Nikki are drawn into a war between a medical research establishment and a group determined to take direct action.

With Nikki missing, Harry works against the clock to find out who is responsible for the murders and finds himself in a cover-up.

Harry and Nikki are first on the scene when an RAF helicopter crashes, but Harry's search for answers brings him into conflict with the Ministry of Defence.

Harry suspects the Ministry of Defence may be covering up the true cause of the helicopter crash, but he's determined to get to the truth.

When the mutilated body of a young boy is pulled from the river, Leo is determined to give him an identity and to bring his killers to justice.

Leo refuses to back down in his search for the killers of the young boy, despite threats and increasing racial tension.

The murder of a John Doe leads the team to a hospital, where Nikki is investigating a top paediatric surgeon with an unusually high mortality rate.

With Nikki out of action and Alice's surgical team closing ranks, Harry and Leo dig deeper.

Nikki revisits an emotive case from the past when a girl she proved innocent of murder is herself murdered.

Nikki grows increasingly worried that a mistake she made on a case four years ago may have contributed to the murder of a young woman.

When the bones of a young girl are found, everyone but Nikki is convinced it's a teenager who went missing two years ago.

Having fallen out both with both the police and Clara's family, Nikki finds herself increasingly alone in her search for the killer.

Leo does community service on a rough estate after being done for drink-driving.

Frustration within the team builds as Harry and Nikki struggle to find any useful evidence from the post-mortems to help the police. No one will talk, and they have no leads. Leo worries for Levi, who is sucked further into a world of gangs and violence.

The team investigates the murder of a woman found dumped on the side of the road with her face removed.

Harry tangles with a Russian oligarch over the murder of a journalist.

The team investigates an armed raid on a suspected terrorist cell in which two suspects and a police officer are killed.

Nikki faces mounting police hostility to her investigation of the armed raid.

Harry is drawn into the murder of a Hasidic man found on disused wasteland, while Leo investigates the death of an Australian backpacker.

A second Hasidic boy is killed, which convinces Harry they are looking for a Jewish killer.

When one boy is found dead and another is abducted, the team faces a race against time to find the missing child.

As the search for Liam continues, Nikki's loyalty towards her former mentor is tested.

The team is asked to investigate the death of a British medical student in Zambia.

Nikki clashes with Zambian police as she investigates the death of a British medical student.

Leo comes under suspicion for fraud when an insurance investigator accuses him of falsifying a post-mortem report, and Harry falls for the charms of an attractive former colleague.

Harry puts his career on the line to prove his lover's innocence after Leo is attacked and Levin turns up dead.

Harry and Nikki try to remain professional when they find themselves on opposite sides of a high-profile case, but it's not easy as they're both brilliant at what they do, and they soon show that every piece of evidence can be interpreted at least two ways.

The revelation that Flannery's first wife also died of a stair fall sends Harry to Prague to seek evidence to prove the man's guilt. However, Nikki's determination to look beyond the police's blinkered investigation leads to further tragedy.

Leo is concerned that the police are involved with a cover-up to protect a rogue undercover cop linked to the death of a young woman.

With Danielle missing and her lover on the run, Leo and the police struggle to unravel a complex web of deceit.

Nikki and Harry try to help wounded victims of a campus shooting while trapped in the building with the rampaging shooter.

Leo's postmortem of the victims reveals there were two guns used, and possibly a second shooter.

When a Zimbabwean asylum seeker is unfairly deported to South Africa, Leo needs to find a way to help her return to the UK.

Nikki is forced to make some hard choices when she discovers that Anton has been less than honest with her.

When the pathologists investigate three suspicious deaths in one night on the same ward, it looks like hospital staff may be behind their murders. Nikki becomes increasingly disturbed by a rape and murder case involving a young child.

Nikki's mental instability worsens, and Harry and Leo are forced to get her psychiatric help. But then when the true identity of the murderer is discovered, it becomes a race against time to save Nikki's life.

Leo finds himself haunted by past memories when he returns to Sheffield after an ancient body is unearthed on Bleaklow Moor.

Leo investigates a potential copycat killing, but the team are starting to wonder if Karl Bentley was wrongly convicted, leaving the real murderer free to set out on a new killing spree.

As Nikki investigates the drowning of a young mother, Harry is called to an apparent suicide at a nearby army base; it soon starts to look like the cases may be linked.

Having established that Lieutenant Lockford was murdered, Leo makes a startling breakthrough, and the investigation begins to unmask a dark secret at Hillsdon Army Base.

When human rights lawyer Anna Sandor calls Harry to Budapest to investigate the death of a client, they start to uncover a sinister underworld conspiracy, putting both their lives in danger.

With Harry dead and Leo and Nikki getting nowhere with the police, the pathologists struggle to clear Harry's name, while the police seem intent on covering up a wider conspiracy.

After a major incident at the Dutch Embassy, Harry and Nikki are removed from the case when the Dutch decide to appoint their own pathologist.

When the Van Burens' au pair commits suicide, the pathologists start to unravel the truth behind the embassy shootings, and a dark family secret is exposed.

When Leo's friend commits suicide, Harry and Nikki are called to the scene of a violent and calculated murder, which is thought to be the work of an apparently dormant serial killer.

Harry and DI James deviate from the original investigation to secretly test DNA evidence from the rival Chesham laboratory to try to solve this stalled case.

Harry is disturbed to be called to a crime scene at the home of a family he knows, and finds the bodies of the mother and her teenage daughter, while her stepson lies in a coma - although her toddler has been left unharmed. The police suspect the woman's husband to be the killer - but the pathologist is not so sure of his guilt. The double-murder investigation reveals more about the tangled lives of the inhabitants of Magnolia Drive

Harry and Nikki delve deeper into the tangled lives of the inhabitants of Magnolia Drive.

Serial killer Arnold Mears Eenjoys poetry but has no remorse for violently killing three teenagers. He has been busy for the last five years sending Annie, a desperate mother of a missing girl, on secret hunts to try and find his hidden victims.Annie’s son Andy, upset at Mears’ manipulation of his mother, ends up turning to Nikki for help. Leo manages to get himself into tropuble with the team after he re-examines a case by Nikki’s old mentor, Dr. Helen Karamides.

Nikki manages to track down the original detective on the case, Detective Inspector Gladwyn ans she looks around the church that killer Arnold Mears used to attend as a boy. Mears is not happy that the police have been made aware of the undiscovered bodies and he says that he is prepared to reveal where he has hidden them to Nikki.

Prison officer Daniel Kessler and Ellis Roberts refuse to reveal anything after child-killer James Wade suddenly dies in his cell. Harry meets Wade’s sister Miriam and agrees to help find her brother’s killer

The team continue to investigate the murder at the notorious Redhill prison where the efforts to control the drugs trade on the wing continue. Harry and Nikki take a good look into Detective Inspector Bridges’ past, and make a significant discovery.

One of Delaney’s patients, Eve Gilston, is discovered dead in her bed. The coroner’s verdict is sudden arrhythmic death syndrome but Delaney is not convinced and gets Leo to investigate. Suspicion soon falls on Eve’s dad Anthony, who lost the family fortune, and his wife Beth.

Leo is determined to learn the circumstances about the death of Eve Gilston. Nikki and Harry manage to find the nun who performed the exorcism but are surprised by what they find. Eve’s mother Beth Gilston is confronted by Leo and che omes close tod iscovering the truth about what actually happened the night before her daughter died.

Nikki stumbles across a sinister underworld where teenage girls are groomed for sex and forced into prostitution.

Harry and Nikki make a crucial connection between the dead girls and sex-grooming victim Shannon, but is it too late for Hannah and Lauren?