What is the movie All the Devil's Men about?

The movie 'All the Devil's Men' is about a former Navy SEAL, Jack Collins, who now works as a bounty hunter chasing terrorists for the CIA. However, his reliance on medication to cope with his inner demons makes him a liability to the organization. He is given a final chance by his CIA handler to prove himself on a mission in London, where he must track down a rogue CIA agent who has gone missing after buying weapons of mass destruction from Russian mafia.