Mouk and Chavapa are in the Andes. While they are running some errands, the bus leaves with their bikes attached to it! Api is going to help them catch up with the bus… by mule.
Mouk are Chavapa are in Africa, visiting their friend Bouba. Today, they went to watch the birds and record them singing, but when they came back, Chavapa's bike had disappeared. Chavapa is very sad. What happened? Who took his bike? How are Mouk and Chavapa going to continue their world tour?
Mouk and Chavapa travel by bus in the outback with Sidney, his father and two other passengers: Nina and her grand-mother. Unfortunately, the bus breaks down and there no water left in the radiator. Luckily, they find a watermill and try to repair it.