A bold experiment to bring fierce African wild dogs back to Gorongosa National Park in Mozambique reveals how predators—and the fear they trigger—play a surprising and crucial role in keeping wild ecosystems healthy. Until recently, the impact of predators on ecosystems was thought to be simple: predators eat prey, keeping their populations in check. But more and more, ecologists are realizing that it’s not all about consumption. In fact, just the presence of predators can cause significant changes in behavior. Scientists call this the “Landscape of Fear,” and in Gorongosa, they are hoping to harness its effects to help bring an ecosystem back from the brink.

It’s a grand experiment with risks all around. Will the rare wild dogs survive the relocation, bond into a pack, and find a new home in the park? Will their arrival harm prey species recovering from a war that shattered the lives of humans and animals alike? Or will the wild dogs set this fabled national park on the road to health and balance, and be a beacon of hope for environmental recovery efforts worldwide?