Seconded from MI5 to the SIS, Paul Tallis faces his most explosive mission yet: following a series of high profile killings, the Russian government has become even more authoritarian, and for Tallis, it's about to become personal. It's feared an old friend has turned rogue, and Tallis is sent to bring him in, but for the first time, he isn't sure whose side he's on, and which side he "wants" to be on.