Luke Hanson has recently been released from jail after serving 8 years for setting a fire at his local school in which the caretaker had been severely injured. He was across the country committing another crime at the time and would like the team to reopen the case. This was Jack's last case before retiring to care for his wife, who was the victim of a hit and run driver. Supt. Pullman gets an offer of promotion that she is finding very hard to resist, but it would mean leaving the squad. A woman who claims to be his daughter approaches Gerry, and Brian rekindles an interest in war gaming. In the course of investigating the school fire, Jack learns the identity of the hit-and-run driver and decides to take action.

Jack's finally discovered the identity of the hit-and-run driver who murdered his wife and he is now prepared to risk everything to kill the man responsible: crook Ricky Hanson. Determined that Hanson should meet the same fate as his wife, Jack lies in wait in a pub car park, engine running. Sandra becomes aware of the situation. She acts fast to prevent him confronting his nemesis, but it results in a crash that jeopardises the future of the entire team. With Jack, Gerry and Brian hospitalised, Sandra's forced to accept temporary help at UCOS from the super-efficient DCI Karen Hardwick, a woman who irritates Pullman on every level. As she struggles to keep the truth behind the crash a secret from Strickland, Sandra becomes deeply suspicious that Hardwick's been recruited to spy on her. And with Jack clearly on the edge and suffering temporary memory loss since the crash, Sandra has her work cut out in trying to keep Hardwick in the dark. Threatened by a new face in the office and desperate to prove that they're still a crack team, even from a hospital bed, the boys need a case. When their consultant, Dr Finlay McKenzie, mentions the suspicious death of a patient, Alan White, on their ward 10 years ago, they seize the opportunity to re-investigate, hoping it will hold the team together. But is Jack still in mortal danger from his nemesis?

The trial of Ricky Hanson starts, and the members of UCOS are scheduled to appear as witnesses. Hanson is the man who killed Jack Halford's wife, but he's on trial for attempting to murder Jack, who was recovering from a car accident over a year ago. Hanson's barrister is clearly out to discredit each of them individually. While at the courthouse, they are asked by an acquaintance of Jack's, Sam Tallis, to look into the death of Ralph Wheeler, who was killed and left his fortune to a tart named Carrie Soper. As they look into the case, they find several possible suspects, including a solicitor, a doctor, and someone with a lengthy criminal record. In the end, the case revolves around a car accident and organ donation.

The team meets a girl called Jo, who is heckling Right Wing comedian Ray Harris. Her aunt Sarah Jones and Sarah's partner Daniel disappeared twenty-five years earlier whilst engaged in a campaign against Ray's sexist and racist routines. The pair actually infiltrated an extreme group of Nazi supporters called the Twenty-Fours, which numbered Ray, policeman Frank Paterson and Ricky Hanson who killed Jack's wife. Frank was also undercover,trying, unsuccessfully, to bust Hanson's drug racket but now joins with Sandra to nail Hanson once and for all, with unexpected help from Hanson's son Luke, who has made a shocking discovery about his father. Ricky Hanson is charged with murdering the couple - and, at long last, there is closure for Jack too.