Liz Carlyle has been transferred to Counter Espionage, along with her research sidekick Peggy Kingsolving. Once the hub of MI5 operations, the department has been reduced in size since the end of the Cold War, and priority within the service is on counter terrorism. Yet there is plenty for Liz to do. In fact, there are more spies operating in London today than during the height of East West hostilities. This includes Russian spies, who continue to operate in number. What's changed is their targets.