The BEST episodes directed by Ben Wallis

#1 - Invasion of the Killer Whales

Nature - Season 33 - Episode 6

A shift of power is taking place at the top of the world. The Arctic is undergoing a dramatic change, and with this change one iconic Arctic hunter may soon have to give way to another as solid ice turns to open sea. The polar bear, once king of the North, needs ice to stalk its prey. Killer whales, or orca, on the other hand, are unable to hunt in an ocean locked in ice. As the ice increasingly disappears, the tables have turned. Polar bears are struggling to survive while the now open ocean provides bountiful new hunting grounds for the whales.