A thousand elephants, from magnificent bulls to vulnerable orphans, come together in a crucial annual gathering in northern Kenya, facing deadly threats from both predators and poachers. Liz Bonnin leads a team of scientists and filmmakers using cutting-edge satellite-tracking technology to follow individual elephants' day by day as they cope with their daily challenges.

100,000 caribou face bears and wolves, deadly frozen rivers and rugged mountains as they undertake the world's longest land migration, traveling 5,000 kilometers through frozen Arctic wilderness. Using cutting-edge technology, Liz Bonnin and her team follow the herd, providing insights into the individual lives of the animals. The caribou must reach their calving grounds before they give birth.

Thousands of zebra face lions, hunting dogs, drought and starvation as they undertake the world's most recently discovered migration. Braving one of Botswana's most brutal wildernesses, they make Africa's longest land migration to reach rich pastures. Liz Bonnin leads a team following the zebra on the ground, every step of the way, to reveal the secrets behind this brand-new discovery.