Master spy Will Cochrane must catch a missing Russian defector as well as one of Europe's deadliest assassins in this action-packed follow-up to Sentinel, written by real-life former field officer Matthew Dunn.

Will Cochrane monitors the nighttime streets of Gdansk, Poland - waiting for the appearance of a Russian defector, a man bearing a top-secret document. Will believes the defector is about to step out of the cold and into the hands of Polish authorities, but suddenly everything goes sideways. The target shows up, but so does a team from the Russian foreign intelligence service SVR, and they are hell-bent on keeping the man from walking. Then, in a hail of cross fire, a van speeds into the melee and snatches the defector out from under them all. Everyone wants the man and the codes he carries - but now he's gone and it's up to Will and his CIA/MI6 team to find him before the Russians do.

Will tracks both the missing Russian and his kidnappers, believing the defector has his own warped agenda. But soon it's apparent that the real perpetrator could be someone much more powerful: a former East German Stasi officer who instigated a super-secret pact between Russian and U.S. generals almost 20 years ago. An agreement, which if broken for any reason, was designed to unleash the world';s deadliest assassin.

Then Will learns that the Russians have tasked their own "spycatcher" - an agent just as ruthless and relentless as Will - to retrieve the document. Now Will knows that he faces two very clever and deadly adversaries, who will stop at nothing to achieve their aims.