S1.E3 ∙ Alaska's River Race

THE LONELIEST WHALE is a cinematic quest to find the "52 Hertz Whale," which scientists believe has spent its entire life in solitude, calling out at a frequency that is different from any other whale. As a group of scientists mount an expedition to locate this elusive creature, the film delves into the profound interconnection that exists between whale culture and our own.

Pioneering scuba diver Valerie Taylor, who has dedicated her life to exposing the myth surrounding our fear of sharks.

Diving Into The Darkness is a jaw-dropping yet intimate portrait of cave diving icon Jill Heinerth, and the nail-biting challenges and risks she's faced to go where no man or woman has gone before.

A visually stunning chronicle of what it is like to live in Antarctica for a full year, including winters isolated from the rest of the world, and enduring months of darkness in the coldest place on Earth.

Meet Mara, an endearing lion cub striving to be like her mother; Sita, a cheetah and single mother of five; and Fang, a proud leader of the pride who must defend his family from a rival lion.

Two men explore the high-altitude wilderness of Tibet with many cameras, filming wildlife from a respectful distance and searching for the rare snow leopard.