We document the two apex predators of Yellowstone - the grizzly and wolf as they once again meet head-to-head, vying to emerge on top. Grizzlies once reigned unchallenged as the top predators of Yellowstone, but everything changed when an old rival returned to the landscape. After almost a century without them, wolves were reintroduced to Yellowstone and again play a vital role in the ecosystem that depends upon them. Once the sole rulers of this vast kingdom, grizzly bears are now re-learning how to cope with the rise of an equal competitor.