During the age of dinosaurs, trees began producing a sticky, protective resin that traps and entombs everything it touches. The hardened, honey-colored resin, known as amber, opens a unique window on a lost world of vanished animals and plants, often preserved in exquisite detail. Here, Sir David Attenborough investigates a wealth of embalmed animals and plants, tracing them back to their fascinating origins in the forests of 40 million years ago. 56 min.