Working in secret for years to solve the puzzle in the writings of the 17th-century astronomer Johannes Kepler, Ivan Volkov, after the loss of his son and Russia's invasion of Ukraine, makes the fraught decision to contact the CIA, risking his life to help stop the Doomsday clock.

Wrapping up his latest assignment for the Magellan Billet, Luke Daniels receives a surprise visit from the head of a former-CIA operation named Sommerhaus -- a failed attempt to assemble an espionage network within the Ukraine on the eve of the Russian invasion. Sommerhaus ranks high on Luke's list of painful regrets for it was during this mission that his friend, CIA case officer John Vince, was captured by Russian operatives and supposedly executed....

"Former US Air Force officer Nick Flynn joined the clandestine Quartet Directorate to continue its long-standing mission: to act decisively against serious threats to the free world. And with the backing of Russia's authoritarian president, no threat is more deadly than that of Pavel Voronin and his mercenary Raven Syndicate. Twice they have almost succeeded in bringing the United States to its knees, only to be stopped at the last moment by Flynn...