A young English boy of 15 is a valet to his overlord and travels with him and his knights on a pilgrimage to the Holy Land, joining thousands of other Europeans to regain ground lost to the Saracens. This venture became known as the Second Crusade.

He saves the life of Eleanor of Aquitaine, who at that time was travelling with her armies, together with her first husband, the King of France. Later, after an ill-advised crusader attack on the city of Damascus, which ended in their defeat, the boy is wounded, captured by the Muslims and thrown into a dingy prison cell.

Eventually, he is rescued by an 11-year-old Muslim boy, who eventually becomes the greatest leader of the Muslim world, Saladin. He and the English boy, Crispin, become firm friends. He becomes a trusted assistant to Saladin and accompanies him during his many adventures and wars to unite the Arab nations. Crispin runs the pigeon communication services, which are essential to Saladin's objectives.

During these years, Crispin marries Yasmine, and they start a family. For over 40 years they create a magnificent book with beautiful paintings, which details their life experiences and encompasses the history of their times. This is their Magnum Opus.

Many years later, King Richard the first arrives and leads a terrible campaign to defeat the Muslims and regain control of the holy city of Jerusalem. At the conclusion Crispin has an opportunity to return home, but deeply regrets the decision he made.

Crispin had been born with just one arm........