Nigel Marven materializes in Mongolia, Planet Dinosaur. He explains to the cameraman why he is here: he is seeking the owner of a giant claw. Just as he finishes explaining, a Saurolophus tramples his tent. Nigel Marven then gets up close to the Saurolophus and he is surprised when the huge herbivore splatters mucus all over him. After that, Nigel crosses a nesting colony field of Protoceratops. Then he journeys through a forest which is likely to harbour the likes of Therizinosaurus, the owner of the giant claw. On the way, he spots some Velociraptors and he watches as they kill and eat a wounded Protoceratops. He then sets up base camp in a clearing. He picks up a scorpion and puts it in a jar, calling it his 'pet.' Then he retires to his tent, only to be disturbed by some small omnivorous dinosaurs. He chases them and catches one. He comments on the creature's remarkable down before setting it free. After that he returns to his tent, only to find his scorpion eaten. He curses the omnivores and goes to sleep. The next morning he finds a nest of Therizinosaur eggs. The nest has been broken into by egg-eaters. He finds a Therizinosaur embryo and he remarks on the claws before carrying on with his search. He also finds some herbivore droppings. He scours the forest before spotting a Tarbosaurus. He quickly hides and watches fearfully as the Tarbosaurus walks past him. After that he goes to a waterhole and waits patiently for a Therizinosaurus to turn up. Some Velociraptors stalk him, however, and he is forced to run for it. He climbs onto a huge tree stump, and he scares the Velociraptors away with a bicycle horn. Then he returns to the waterhole to find a Tarbosaurus. He hides again and watches as a Therizinosaurus emerges from the forest. The two dinosaurs clash but the Tarbosaurus backs down after the Therizinosaurus claws it's face. When the Tarbosaurus retreats into the forest, a herd of Therizinosaurs exit the forest and graze on the surrounding vegetation. Nigel Marven realizes that the Therizinosaurus is a herbivore, and that it's giant claws are used for raking down plants, not for vivisecting prey. He decides to end his quest by touching one of the Therizinosaurs. He succeeds, but the Therizinosaurus licks his face. The credits come to a close as Nigel Marven lies on the ground. The BBC logo kicks in just after Nigel watches the Therizinosaurs walk away.