In 1925, a deadly outbreak of diphtheria tore through the small Alaskan town of Nome. The closest point that antitoxin was available was 674 miles away. 20 of the most respected dogsled mushers were chosen to transport the antitoxin to Nome in a 5 day relay.  

Leonhard Seppala was to undertake the longest and most dangerous part of the journey with his 12 year husky, Togo, as his lead dog. Seppala and Togo faced average temperatures of minus 30 degrees, with temperatures falling as low as minus 85 degrees in the gale force winds. When their sled was almost across the Norton sound, they found themselves stranded on an ice floe. Tying a lead to Togo, Seppala tossed Togo over five feet of freezing water to shore. Amazingly, Togo could then pull Seppala and his entire team to safety. Togo and Seppala traversed an astounding total of 264 miles.

The mushers and their dogs completed the Serum Run in 5 and a half days without one single vial broken, saving Nome.