During the Third Crusade, Roger, a runaway English monk unjustly accused of murder, arrives in the Holy Land, where he becomes a common soldier and takes part in the siege of Acre. Jammed into the crusader camp are more men than in all the great cities of Europe combined. While the army awaits the arrival of Richard the Lionheart and Philip of France, men die by the thousand from battle, disease, and starvation, until it seems as though the entire force will perish, and the fate of the crusade hangs on a knife's edge.