One evening, all of the children are hospitalized with diphtheria, and Curtis Welch waits to get antitoxin. Severe winter weather conditions prevent medicine from being brought from Juneau by air or sea, and the closest rail line ends in Nenana. A dog race is held to determine the best-fit dogs for a sled dog team to get the medicine. Balto enters and wins, but Steele exposes his wolf half, causing his disqualification. The team departs that night with Steele in the lead and picks up the medicine successfully, but on the way back, they end up stranded at the base of an icy hill, with the musher unconscious.