Detectives Carrigan and Miller are thrust into the terrifying world of stalking and obsession when a drugged and distressed young woman arrives at their station claiming her friend has been abducted. Taking them from a backpackers' hostel in west London, to the world of online intimidation, hacking and control, The Intrusionsexplores themes of dark psychology as Carrigan and Miller hunt for the shadowy figure behind a frightening and spiralling campaign of intrusion . .