In the second film of the voyage of the oceanographic vessel Calypso, Jacques Cousteau and his team of scientists have reached the Indian Ocean. They test Cousteau's specially designed mini-submarines, which enable them to film underwater the mating behaviour of the great Green Sea Turtles.

In the depths of a Russian forest a Red Deer calf is born. Throughout the contrasting seasons of his first year he encounters all kinds of fellow creatures, including a bathing bear, beavers, a menacing lynx, and a pack of hungry wolves.