Forensic pathologist Dr. Sam Ryan returns to Cambridge to take up a teaching assignment and to work for the police as required. In her first case, she has to deal with the death of a six year old girl find floating in a nearby river. The autopsy reveals that the child has suffered previous abuse, including cigarette burns and several broken ribs. Sam receives information from a prison inmate that implicates someone in a previous death and Sam suggests a radical step. In her personal life, Sam has to deal with her elderly mother who is showing signs of dementia and her sister Wyn with whom she has a strained relationship.

With the exhumation of a child that had died from abuse some years earlier, Sam is able to demonstrate that there are similarities between the deaths of the two children. There is also only one individual with a connection to both cases. When Sam's house is broken into, her personal safety is a risk but she pursue the case with her usual zeal.

When Mark James' decomposing body is found in an abandoned building, there is every indication that he was part of some occult ritual. An upside down cross was carved on his chest, his wrists were bound with ivy and he was strangled. All evidence points to his friend Sebastian Bird, a rich idler who allowed James to live in his house but who had also developed a expert knowledge of the occult before being sent down from Cambridge for having had an affair with a professor's wife. Sam Ryan's testy relationship with the police continues as she is having difficulty establishing a forensic link in the case and also for publicly criticizing the well-liked Police Surgeon, Dr. Richard Owen, for attending the crime scene without the proper protective clothing. Sam also has to deal with her rebellious nephew Ricky, who is constantly fighting with his mother and announces that he has left home to move in with her.

Sam continues her investigation into Mark James' murder. When another of Sebatian Bird's one-time friends is killed the police are ever more convinced of his guilt and grow increasingly frustrated at Sam's inability to provide them the evidence that they are sure is there. The solution lies in an old case and someone's desperate need for revenge.

Sam investigates the death of a gay man while in police custody. He had been arrested while drunk and was sharing a cell with another drunk, in for the night. The victim died from a blow to the head and was badly beaten post-mortem. DS Farmer is concerned that the assault may have been the work of some of her officers. Sam also meets up with Liam Slattery an old friend she has not seen for 20 years. Sam's sister however is convinced Liam was responsible for the death of their father years before.

Sam continues her investigation in the prisoner's death and believes the police are covering up. When a police constable whose wife reported was cracking up is found dead, the investigating officers themselves believe something is amiss. Sam continues to be harassed by someone unknown and has to call in the bomb squad when she receives a mysterious parcel and subsequently someone tries to run her off the road. Liam and Sam renew their relationship but she is faced with a difficult choice.

One of Sam Ryan's students has a problem and seeks some personal advice. She and her family immigrated from Vietnam during the boat people exodus and her father wants her to enter a marriage he's arranged for her. She's worried that her husband to be will realize she is not a virgin and Sam counsels her that honesty is always the best policy, but in this case it drives the prospective groom to violence. When the family's restaurant is burned out, the police find a badly burned body. On the home front, Sam continues to bicker with her sister Wyn about whether their mother should be placed in a home and the bitterness over their father's death continues to divide them.

DI Adams and DC Cox's personal relationship is now affecting their work, leading Cox to request a transfer. With the burned body now identified through dental records, the police have a suspect. However, he suffers from post traumatic stress disorder and the police are concerned that he may lash out. When the police do finally locate him, a member of the team is killed.