Azur left the Siberian Rainbow Town with the wanderers, as an interpreter and secondary hacker who joined the Rainbow Town Freedom Team out of curiosity, then the Rainbow Towns Band after the aliens' defeat.The band's World Tour over, Azur wants to go home, as do Toby and Gaia. From Paris to Siberia by steam-train, they reach his hometown where they start building their own airship, to be able to move around more easily.A sensational journey across future Earth, trying to uncover more mysteries, be it with Airship Siberia or the Wind Rider. A thrilling science fiction story.