Justin Gilead is an agent with the CIA.
Gilead is, in fact, the best agent the CIA has ever had. His archnemesis, Alexander Zharkov, is the head of Russia's most secret Intelligence agency. Both are excellent chess masters with the ability to plan far ahead of most opponents. Both have reasons for hating the other, beyond the ideological differences of their respective countries.
As the series opens, Gilead has been thought dead for four years. When a CIA agent in Russia sends out a golden snake medallion, it alerts his bosses that Gilead is still alive and the rush to reach him starts for both his side and the opposition. The bulk of the two books remain the conflict that occurs after he is back.
This series is really about both characters, though Gilead is truly the main protagonist. Both characters are similar in so many ways. They were born on the same day. They are both chess prodigies, indeed meeting for the first time at the young age of 10 when they had their initial tournament facing. They would both reach chess grandmaster status early and then move into their separate clandestine roles. As similar as they are, however, they are diametrically opposite when it comes to philosophy and morals and for that reason they are the bitterest of enemies.
Even more than a spy series, however, this two-book series is a battleground between good and evil that is played on both the physical and metaphysical stage. Gilead represents the Good side while Zharkov is Evil. Whether these two gentlemen chose their respective sides or the sides chose them is something the reader is left to decide. The authors do a very good job of presenting this conflict inside the cover of espionage work at its finest.