Assistant Chief Constable Desmond Iles lost a man in a undercover operation and will not attend the police undercover conference held by his colleague ACC Esther Davidson.

Davidson lost a case involving the Corman Turton Guild. She decided that the only way she can get the goods on them is to infiltrate the organization by the process known as "out location". She must set up her out location without the advice of Iles. The undercover officers face possible death if uncovered. Her undercover operation continues while she is involved in a trial involving the murder of a policeman who went undercover.

James discusses the political and legal considerations of out location and gives complex details on choosing the officers to go undercover. The writing is outstanding, brief, to the point, and with some wit.