Best friends Jack and Gilbert made a pact when they were younger - promising to work together in the copper mines, just like their fathers and other Cornish immigrants. But now Jack is turning twelve, and the thought of working underground fills him with panic. When Gilbert is forced to leave school and earn a wage, Jack wants to keep his word to his friend - but that means facing his fear. And all the while his heart is telling him to follow another path. That boy, Jack must find the courage to choose.