Dolf helps the children defy the terrible mountains, conquer disease and fight evil knights. Slowly, Dolf begins to realize that the real danger does not lurk behind the next mountaintop, but rather within the crusade itself.
A time machine catapults a twentieth-century teenager -intelligent and headstrong - to the thirteenth century. Rudolf Hefting of Amsterdam thought the was engaged in an experiment that would take him back to the Middle Age to a tournament of knights.
“He had wasted his four hours time-travel in chatting, doing sums and even fighting. He had nothing to show Dr. Simiak from the Middle ages. It would not be of much value to tell him about the fascinating Leonardo.”
Fifteen-year-old Dolf uses a prototype time machine and gets stuck in the Middle Ages. Trying to find his way back to the twentieth century, he joins a children’s crusade of almost ten thousand children on their way to the Holy Land.