Spring, 1096. Europe's princes march their armies toward the Holy Land. They are accompanied by tens of thousands of pilgrims, led by a fiery preacher Peter the Hermit. Their destination is Jerusalem, the holiest of all Christian cities. Their goal is to conquer the Muslim occupation. History will call them the First Crusade.

Among the pilgrims is Oderic of Rheims, a Benedictine monk from eastern France. He's devoted to the cause, but the Crusade will test every vow he swore to the Church. His poverty will be challenged by greed, his obedience tempted by blood lust. But it's his oath of chastity facing the greatest trial, in a deep, secret love for Rebecca, a Jewish woman Oderic rescues on the long road to Jerusalem.

The four-year journey is filled with unimaginable hardships and dangers: terrifying Turkish armies, impregnable cities, a death march, starvation, excruciating thirst, desertions. Ninety percent of the Crusaders will never see Europe again. As Oderic evolves from priest to warrior to lover, he realizes he will not return to Europe the same man. If he returns at all.