In the winter of 1925, the terrible suspicions of the only doctor in Nome -- a small, isolated town in northwest Alaska -- came true. A highly contagious and deadly disease called diphtheria was spreading, and he sent word asking for a delivery of the medicine to cure it. On February 2, 1925, Nome received its first delivery of antitoxin, transported by some heroic couriers: dogs! Sled dogs, braving the treacherous elements of a freezing Alaskan winter. But just one of those dogs would become legend.