Former New York City mayor Tom Cafferty has been haunted by the horror of that single day: the opening of the brand-new Z Train subway line beneath the Hudson River—the supposed shining pinnacle of his tenure. But the ribbon-cutting ceremony turned deadly when the train carrying Cafferty’s wife and other citizens was attacked by a horde of hyperintelligent, bloodthirsty creatures previously unknown to humanity.

Everything changed for Cafferty, ex–NYPD officer Sarah Bowcut, and tech expert Diego Munoz that day. And they had uncovered another deadly truth: the attack was no accident.

The creatures that wreaked havoc underneath New York have now spread worldwide, and facing a massive cover-up—and a secret organization holding whole nations hostage—Cafferty’s team must fight against impossible odds to save the entire planet from an apocalyptic disaster.