The Commander
Clare Blake, a high-ranking, ambitious officer in the Metropolitan Police's Serious Crimes Unit, leads complex murder investigations that often blur the line between her professional and personal lives.

Eric Thornton and John Littlewood figure prominently in hospital files, but when it's confirmed that Littlewood has died, the police focus all their effort on Thornton. A dark history of mental problems and violence related to them, Thornton stands out as the prime suspect in the girl's murder, but when his own mother (Celia Imrie) is murdered in cold blood, James isn't convinced that Thornton is responsible for either death.