John Luther is a Detective Chief Inspector (DCI) working for the Serious Crime Unit in the initial season of the crime thrilling series. A dedicated brilliant police officer, but deep inside him is a possessed, struggling and sometimes dark and violent man. His obssesive dedication makes him constantly the centre of the darkness of the crimes he encounters. John investigates brilliant psychosis and killer Alice Morgan, but he is unable to put her in jail due to lack of evidence, but as the quest on her progresses, she becomes both his nemesis and unlikely partner.