One of their guides, Joseph, seems to sense an odorous smell on the wind. Whatever the smell is, it terrorizes him greatly – so much so that he breaks and runs off into the night. Simpson goes looking for him and picks up his tracks – as well another set. The night proves to be an eventful and horrifying one, eventually ending in tragedy. Only Punk, their Indian cook, seemed to understand what had happened after noticing the smell that Joseph carried.
“For sheer naked concentrated horror, unexplained and unexplainable, such tales as “The Wendigo”… may be said to lead among the stories of the supernatural. – Grace Isabel Colbron
The Wendigo by Algernon Blackwood, while not the inception of the creature, helped popularize it in popular culture. Before Blackwood, the wendigo has its roots in Algonquian folklore. It is reported to be a man-eating creature or spirit that is native to forests of the Atlantic Coast & Great Lake Regions of Northern America.
You can learn more about different monsters in The World of Lore: Monstrous Creatures by Aaron Mahnke and more about the wendigo in particular in Dangerous Spirits: The Windigo in Myth and History. You can also purchase collection of two stories by Blackwood – this one and The Willows – at this link.