The Polar Light had entered the devil's north wind area of the Oro Strait on the second day since it left Saint Herner Island. From then on, it started to cross the sea.
As a strait in the southernmost part of the Ice and Snow Wildness, the Oro Strait was the only route from the Ewentra Archipelago to the Ice and Snow Wildness in the north. Not until Zhang Tie came to Oro Strait did he understand why they could only enter the Ice and Snow Wildness by sea. The reason was that airships didn't work in this region at all because of the terrifying devil's north wind area in the Oro Strait.
During the past year in Hidden Dragon Palace, Zhang Tie had learned a lot. At least, he had read the creation of the devil's north wind area in Oro Strait from the textbook titled "Continental Geography"——a powerful air convection and cyclone between the subpolar low pressure area of the Ice and Snow Wildness and subtropical high pressure area of the Ewentra Archipelago.
