Dahlia and Akira were dashing through the woods. They had to take a different route as a horde of flying beasts had blocked their way, forcing them to go through the network of underground tunnels before ending up somewhere farther from the floating city. So they had to rush at full speed to try and get to the destination as soon as possible.

Along the way they came across a foggy zone where the great crude oil river was flowing through the forest. It was a highly toxic zone for normal people b