When Sidney Chambers begins receiving sinister anonymous phone calls, he realises he is connected to a series of murders targeting respected figures in the community. Leonard bonds with Hilary as she cares for her dying father, while Geordie's investigation of the killings leads him to a mysterious home for people with disabilities.

Sidney and Geordie struggle to determine the connection between a murder and a number of post office robberies.

When a young woman’s death is covered up, Sidney and Geordie try to hold those responsible accountable for their actions.

Sidney arrives at a Romany camp, but when someone is killed, he is prime suspect.

When a little boy is abducted, personal pressures on Sidney and Geordie come to a head.