'There's going to be a crusade. A boy came to the cathedral and preached. He's going to lead a crusade of children. And we'll take Jerusalem because we're innocent, we're closer to God.

We'll be soldiers for Christ.'Rufus is an apprentice in his father's goldsmith workshop in Cologne, Gemany.

One day he hears a boy, Nick, preach in the city centre.

Nick's message and words are mesmerising and Rufus is spellbound.

He is overcome with the desire to follow the flawed yet charismatic young Crusade leader on his journey to the Holy Land. And Rufus is not alone. Many children are captivated just as Rufus is, and leave their homes and families having fallen under Nick's spell.

But what begins as a journey of innocence turns, terribly, into a journey of sorrow and despair. An extraordinary tale based on a historical event that has resonated through the ages.