In the volcanic highlands where Rwanda, Uganda, and the Democratic Republic of Congo converge, fewer than a thousand mountain gorillas hold their place in a world that has long threatened their existence. Each day, small groups of travelers pay fifteen hundred dollars for one hour in the presence of these creatures — a transaction that is also an act of collective conscience, binding human economics to the survival of a species that shares nearly all of our DNA. The journey to reach them passes through a country still quietly reassembling itself after catastrophic loss, where terraced hillside