In three 29-minute segments this program shows viewers life’s forgotten story, from the Cambrian Period 530 million years ago with the first fish, through the giant sea scorpions of the Silurian, the first land creatures of the Carboniferous, the gi ant reptiles of the Early Permian Period, the extreme heat of the Late Permian Period, to the predecessors of mammals and dinosaurs of the Triassic Era. Letterboxed; DVD includes English subtitles, " Trilogy of Life " (30 minutes) on the making of the "Walking with" programs. Filmmakers Chloe Leland and Tim Haines; narrator Kenneth Branagh. BBC