Gordon Buchanan goes to meet the world's cutest animals to reveal their hidden biology, and find out why people have such a strong emotional response to them.

In the winter of 1959, the mutilated bodies of nine hikers were found in the Ural Mountains of Russia. Were they slaughtered in cold blood by a yeti? If so, what drove this legendary beast to kill? Shocking evidence sheds terrifying new light on the Dyatlov Pass incident.