Felix Brooke, the orphaned son of an English soldier and an aristocratic Spanish mother, has been raised in the strict, loveless household of his grandfather in Villaverde, Spain. When Felix gains possession of a letter that contains a clue to the whereabouts of his father’s family, he gladly runs away from home to pursue the trail. His journey from Spain to far-off England begins the adventure of a lifetime.

After visiting his family in England, Felix is on his way back to Spain when he's shipwrecked off the coast of France. He is taken in by monks to recover from his ordeal—but it soon becomes clear to him that he is actually being held prisoner. Felix encounters an injured boy, Juan, on the grounds of the monastery and saves him from death. The two boys escape and continue on to Spain together—but a gang is pursuing Juan, and the journey is more dangerous than they imagined.

Now eighteen, Felix sets out across the mountains of Spain to rescue three children kidnapped by their father. Along the way, he hopes to see his true love, Juana, who has entered a convent. But his rescue party is being followed, and Felix fears he and the children are being led into a trap.