June 1924. On the brutal North East Ridge of Mount Everest, famous adventurers George Mallory and Andrew Irvine vanish into the snow-whipped night. Daredevil explorer Richard Deacon devises a plan to follow in the men's footsteps. Off piste, with no support team and in the most vicious climate on earth, Deacon and his companions hear howls in the distance. Some dark creature is tracking them up the mountain, sending them scrabbling blindly into Everest's dangerous heights to escape it. Soon they will discover what happened to Mallory's crew - but can they escape the same hideous fate?