This psychological thriller concerns Ali, a London-based female law officer simultaneously involved in a heated and clandestine relationship with her sister's beau and a city-wide police hunt for a serial rapist. When the squads close in on the boyfriend as their number one suspect, it foretells Ali's need to 'lay down her cards' by confessing her relationship to the man in question. But this may mean permanently losing all ties with her sister. Ali suddenly finds herself torn violently in two directions - but she's quickly running out of time, as new details come to light regarding the suspect's background and motivations.
A series of attacks on lone women walking home in Islington leads the Serious Crime Group to believe that a serial rapist is on the loose.
Jay follows up on the theory that a suspect could be the man they are looking for, and when bank statements confirm that the payslip found at the scene of one of the assaults belongs to him, Wilson organizes an arrest.