During World War II, hundreds of people were forced to leave Denmark for British outposts. Set in this time of frenzy, the story of Mark Jensen and his friend Frederick, both thirteen, reaches a plateau high above the level attained by countless mysteries. With Mark's older brother, Christian, the boys land at the rock of Gibraltor, where they ostensibly become shoe shine boys, while they secretly search for the king of smugglers. They have good reason to believe he will give the Danes horses for their underground work. Their plan miscarries, at first, but the trained young saboteurs come through. Mrs. Price has the know-how of an experienced writer, maintaining careful control of her plot, and not losing track of the mystery of characters.