第 21 季 共 10 集
播出时间：2018年1月9日
第 1 集 Moment of Surrender (1)
播出时间：2018年1月9日
Nikki struggles to come to terms with life back home and seeks out fellow pathologist Sally Vaughan for support, only to learn she is nowhere to be found. National Crime Agency investigator Guy Bernhardt asks Nikki to help him by employing pathologist David Cannon, the chief suspect in Sally's disappearance. As Jack, Clarissa and Thomas share concerns about Nikki's wellbeing, a body found in a reservoir is linked to a murder case from 16 years previously. Return of the crime drama, starring Emilia Fox, with Julian Rhind-Tutt and Alex Macqueen.
第 2 集 Moment of Surrender (2)
播出时间：2018年1月10日
Nikki's suspicions about David Cannon are roused further when she discovers blood in the boot of his car an with Thomas's support she takes samples to process. Does it belong to Sally Vaughn? Meanwhile, the uncovering of the body from the 16-year-old murder shines the spotlight on three people who went to the same school. Emilia Fox stars, with Julian Rhind-Tutt and Alex Macqueen.
第 3 集 Duty of Candour (1)
播出时间：2018年1月16日
A series of tragic events are linked to the hacking of a hospital database.
第 4 集 Duty of Candour (2)
播出时间：2018年1月17日
The team wonder if the hack is the only danger as they come under threat.
第 5 集 A Special Relationship (1)
播出时间：2018年1月23日
A US diplomat is shot dead in central London, forcing the team to work closely with the embassy and the FBI.
第 6 集 A Special Relationship (2)
播出时间：2018年1月24日
Nikki is still in shock as the team arrive at Matt's residence but insists on working at the Lyell, determined to help. When analysing crime scene photos and the positions of the victims' bodies, Nikki realises there is a pattern. Together, the team uncover a secret that has been held by those at the very top of the US government.
第 7 集 One Day (1)
播出时间：2018年1月30日
While two care home staff are chasing Kevin McDowd, a young man with learning disabilities and sociopathic tendencies, Nikki and Jack examine a fatal road accident where the deceased is Kevin McDowd's mother. The investigation led by police sergeant Button should be straightforward, but the forensic evidence suggests foul play.
第 8 集 One Day (2)
播出时间：2018年1月31日
The team are determined to uncover the truth about unexplained deaths of patients at a care home. They are desperate to rescue Serena and return her to safety. Unbeknownst to her colleagues in the Lyell Centre, Clarissa allows herself to be admitted to the care home in order to investigate. Her determination to find out what happened at the care home leads her to uncover a shocking truth, but puts her life in danger.
第 9 集 Family (1)
播出时间：2018年2月6日
It is Christmas morning and Nikki is awaiting a call from Matt who is back in the States. Instead, she receives a call to say that the team is needed: a family has been massacred at an enormous property owned by Andy McMorris, the CEO of a haulage company. Greeted by SIO DI Gibbs, Nikki is first on the scene whilst Clarissa is connected to the action via screens and microphones back at the Lyell. Having left his father to celebrate Christmas without him, Jack is just arriving to join them when a gunshot suddenly rings out. With Gibbs lying on the floor with a life-threatening injury, the team realise that the shooter might still be on the grounds. Are they also in danger?
第 10 集 Family (2)
播出时间：2018年2月7日
As the truth behind the McMorris family is revealed, the team is brought together by the conclusion of a shocking Christmas family tragedy. Reuniting with their respective families, Nikki finds her secret Santa gift is a visit from a loved one.
