When Nick Flynn left the US Air Force to join the Quartet Directorate, he did so with the full knowledge that no one could ever know. This covert private force—called Four by its members—promised him the chance to lead his own missions and make his own decisions, though the risks are high. When a former senior CIA executive goes dark, Flynn and his team—including the daring Laura Van Horn—are ready to step in. What begins as a quiet check on his home turns into a firefight against a familiar enemy who is more dangerous than ever.

Russian oligarch Pavel Voronin and his shadowy Raven Syndicate are back in action, supported by Russia’s aging and autocratic president. Voronin intends to unleash a new force of advanced stealth aircraft against the US in order to make Moscow supreme and cement his own rise to power. With millions of lives at stake, Flynn and his team must track Voronin’s operatives and mount a risky counterattack deep into hostile territory. If they fail, the consequences will be horrific. But failure isn’t an option—not for Nick Flynn.