Ben Swan, a young British detective chief inspector working with the Counter Terrorism Command in Ireland, is recruited by the UK Security Service, also known as MI5.
His police rank is suspended and he operates as a full member of the Service. He is given a new cover identity. His police background is not disclosed to his new colleagues. In accordance with MI5 policy, all members operate with a cover identity. He is involved in tracking down terrorists intent on initiating a major bombing campaign and a detailed investigation into the activities of a group of international criminals operating in the UK involving ex-KGB personnel. With this dangerous work he relies on the professionalism, loyalty and trust of his fellow officers. Yet, he knows nothing about their true identities, families or background.  If a member is killed on active service, nothing is made public and there is an apparent absence of grieving within the Service. He finds the anonymity of his existence difficult to accept and this is the theme that runs through the novel. Hence the title: A Secret Existence.