He knows their names and he knows their methods. 

He knows exactly when they’ll strike.

When a desperate man climbs through an abandoned coal chute to reach FBI Agent Cole Keller's office, the warning he delivers sounds impossible: four assassins are planning to execute dozens of congressmen across the United States.

But he waited too long to come forward—and now the killing has already begun.

The most audacious political conspiracy in American history—someone who has built the perfect killing machine—four ordinary people transformed into untraceable weapons, bound by secrets that will die with them.

Racing to beat a conspiracy that operates with surgical precision, Keller moves from the mountains of Colorado to the corridors of power in Washington D.C., pursuing an enemy who is always three moves ahead. Every lead ends in silence. Every witness turns up dead. And the clock keeps ticking toward the next hit.

In a week that will test everything Cole believes about justice, loyalty, and the thin line between dedication and obsession, one question remains: 

How do you stop killers who have nothing left to lose?