When a mysterious man is found in the boot of a Volkswagen Jeta, events are set in motion that has the Service in disarray. Arthur Mann, nowadays a security consultant in Sainsbury's, is brought in for questioning on a fake pension query, but his past reveals odd jobs for the MI5 with "off the books" work for MI6. During questioning, it becomes obvious that the man is not interested in Arthur's wages; rather, he wants to know about an operation called Pastiche that Arthur might've been involved in through a man named Jacob Morrison.
Surprised for having been called in after all these years, Arthur sets out on his own quest for answers. But soon after, the man Arthur reaches out to is found dead in a field carrying Arthur's utility bill. Is Arthur now wanted for murder? What is Pastiche and what is Arthur's connection to it? Who is Morrison, what is ‘Shadow Six' and how are they financed? Or would Arthur be used as a bait to catch a more deadly spy?