Soon after Nicholas' thirteenth birthday, his great-uncle John reveals to him a secret - handed down through hundreds of years to the 'chosen one' in every second generation. John is very old. His house has long since fallen into disrepair, and as Nicholas begins to learn about the fifth key and the pledge, John falls ill. Facing these new challenges and helping to repair John's house, Nicholas begins to discover his maturing strengths. The unexpected appearance of Jake, the traveller whom Nicholas has barely known as his much older brother, heralds a sequence of events that could never have been predicted, and a bond grows between the brothers that evolves beyond the struggles of their ancestors and of Jake's early life.