The film focuses on the event in 1925 when sled drivers and sled dogs worked together to save the lives of children in Nome, Alaska, and rushed on the serum relay road, which was called the "Great Race of Mercy". The film will be available on Disney's own streaming media and will be released in 2019. At the end of 1924, a 2-year-old child in Nome fell ill and the doctor diagnosed him with tonsillitis. This disease is usually not life-threatening, but this child became an exception. Many children were diagnosed with tonsillitis, and several unfortunately died. The doctor finally confirmed that the disease was diphtheria. At that time, there was a vaccine that could be used to fight diphtheria, but all the vaccines in Nome expired, and the new vaccine failed to arrive before the port was closed. The Baltic Sea will not thaw until June of the following year. There is no road directly to Nome, no airplanes, and the only way to transport goods is the postal route, but only sled dogs can pass in winter. The Health Bureau decided to use two groups of sled dogs for relay transportation. 20 sled drivers and 150 sled dogs had to travel day and night, passing rivers, crossing plains, passing through forests, and crossing the frozen Alaska Post Road. The nearest vaccine location is Nanna, 1,085 kilometers away from Nome. Under normal circumstances, it takes 25 days for a dog sled to complete the relay, but they only took 5 and a half days to successfully complete the relay, saving the lives of many children. The protagonist of this film, Togo, is one of the leading dogs used by the Norwegian sled master Leonhard Seppala (played by Dafoe). He is praised for his wit, excellent leadership and keen intuition. Seppala was commissioned to deliver the most dangerous part of the relay, from Nome to Nurato to receive the batch of immune serum, and successfully completed the task in an environment of minus 30 degrees and strong winds of more than level 7. Later, Antarctic explorer Roald Amundsen awarded Togo a gold medal. Bjorn played a relay member who betrayed Seppala on the way.