When Marvik visits his safe deposit box in his London bank and discovers that a three-and-a-half inch floppy disk he had placed there a few weeks previously has been stolen he is surprised and deeply troubled. What is more it has been taken only the day before his arrival by a man Marvik has never heard of. Puzzled and disturbed, Marvik is left cursing his reluctance to ask his former Royal Marine colleague, intelligence and cyber expert, Shaun Strathen, to open the disk and reveal its contents when he first discovered it in the possession of murdered marine archaeologist, Sarah Redburn. Now its theft indicates that Sarah was killed because of its highly toxic contents. Convinced it holds the key to the truth behind the deaths of his parents, Marvik, with the aid of Strathen, sets out to track down the thief. As they follow a trail of abduction and murder it soon becomes clear that the computer disk holds the key to a secret that a ruthless killer is determined must never be revealed.