The defining mission of UN cover operative Mai Fisher's career came in the mid-1980s when she went undercover in the IRA. It was a mission she barely survived, when a shipment of Semtex she intended to destroy before the IRA would distribute it to various cells exploded too soon. Nine people, including a man she'd come to love, died, and she carried the guilt for the rest of her career. Nearly three decades later, a dying soldier has a secret he wants to tell her, one that will change everything.