The Undiscovered Trail follows the path of four slum-dwelling children in the city of Neotropolis. There they live in the city's biggest slum only known as the Thousand Alleyway where they have spent their entire lives scavenging and surviving. On one faithful day, disaster strikes, and one of the four children is separated from the rest of the pack. Their dwelling which had served as their home for many years had been destroyed in the disaster and all hope seemed lost, forcing them to move deeper into the city which they had forbidden themselves from entering.