Ed travels deep into the heart of Siberia to investigate the origins of a mysterious ring of shattered rock, known in local legend as the nest of a giant "fire eagle”. With the appearance of a crater or rocky volcano in the otherwise unbroken expanse of the Taiga forest, the site continues to baffle scientists. Ed knows that cold weather locations are outside his expertise, and so he must rely on the locals for help. Ed is led to a group of semi nomadic indigenous Evenki people, whose reindeer sleds allow him to close in on his mysterious destination despite the bitter sub-zero temperatures, snowdrifts, and arduous terrain. However, the treacherous cold continues to set Ed back and, when he discovers he has frostbite, he must consider giving up.