Held captive at an isolated farmhouse, Dr. Morgan Reese is forced at gunpoint to perform surgery on an Afghan calling himself the Holy Imam. Thus begins the battle of wits between Reese and the Imam. Caught in the crossfire is the Imam's nurse, Miriam, an Iranian-American and devout Moslem.

Reese soon suspects that the Imam is in America for reasons other than his health. The Imam's bodyguards repeatedly talk of a deadline: September 13. Suspecting a terrorist attack is planned on that day, Reese must thwart it. He will need Miriam's help, but can he trust her?

Racing against time, he finds clues that could reveal the Imam's plot: a missing Koran, the final words of a dying man, and a cryptogram. But the grand plan remains elusive—only the Imam knows it.

In the makeshift operating room, Reese confronts the Imam. He knows only one of them will survive.