Follow scientists who are returning predators to their natural environments to restore ecosystem balance.

For most of our time on Earth, we humans have been the hunted, not the hunters. But today, we have conquered the predators at the top of the food chain; wild bears, wolves and big cats are in retreat. Removing predators from the wild has thrown ecosystems off-kilter, triggering domino effects that scientists are just beginning to understand. Follow scientists who are undertaking a simple, but frightening, solution: returning apex predators such as coyotes, bears and panthers to their natural environments. Will these predators restore the natural balance of their ecosystems — or threaten the humans who live among them?