Nathan Tyler is an unassuming professor at a middling American university with a rather obscure specialty in mathematics—in short, a nobody from nowhere. So why is the White House calling? Summoned to Washington, DC, for a top-secret briefing, Nathan discovers that he’s the key to a massive foreign intelligence breakthrough. Reading between the lines of a cryptic series of equations, he could open a door straight into the heart of the Kremlin and change the global balance of power forever.

An 11-year-old boy's violated corpse is found in a town park. Eyewitnesses and fingerprints point unmistakably to one of Flint City's most popular citizens. He is Terry Maitland, Little League coach, English teacher, husband, and father of two girls. Detective Ralph Anderson, whose son Maitland once coached, orders a quick and very public arrest. Maitland has an alibi, but Anderson and the district attorney soon add DNA evidence to go with the fingerprints and witnesses. Their case seems ironclad.

Court Gentry is known as The Gray Man—a legend in the covert realm, moving silently from job to job, accomplishing the impossible, and then fading away. And he always hits his target. But there are forces more lethal than Gentry in the world. And in their eyes, Gentry has just outlived his usefulness. Now, he is going to prove that for him, there's no gray area between killing for a living-and killing to stay alive.

Because within ODIN there is General Operations, which speaks for itself; ODIN 5i, which deals with intelligence gathering, and then there is ODIN 1i which deals in operations so sensitive not even the CIA can touch them. All three are run with an iron first by The Chief, a giant with a gigantic IQ. His top agent is Alex Mason, hard and cool – he's a law unto himself.

Charged with spotting terrorist threats, the top-secret "Campus" has its hands full when Middle East thugs and Colombian drug lords join forces. New Campus recruits include Jack Ryan Jr., son of master spy John Patrick Ryan, now President.