Graham Hoyland, who once found and filmed yeti footprints in Bhutan, investigates our enduring fascination with the ancient legend of this large primate unknown to science. He considers possible explanations for yeti sightings but also delves deeper into the strange world of ‘cryptids’ to ask why we want to believe in the existence of mythical beasts – and what our ‘post-truth’ world can learn from those reports that have been revealed as hoaxes.