Freshwater habitats are the rarest and most fragile on the planet, and this episode of the Our Planet series tracks how animals gamble their survival on water that never stays put. In Australia's Lake Eyre, a colony of pelicans raises chicks on a lake that formed after rare rains, then faces a brutal reckoning when the water dries up and the young birds must fly hundreds of miles to the coast before they've fully learned to fly. High in the Andes, other species contend with thin air and seasonal ice melt that can vanish within years as glaciers retreat. The footage moves between drought-cracked lakebeds, mountain wetlands, and river systems, showing herds and flocks timing entire life cycles around water that appears and disappears on its own schedule. Narration ties the individual stories back to a larger pattern: freshwater sources worldwide are shrinking or becoming less predictable, and the animals built around their rhythms have little room left to adapt.