At Julian's command, everyone disembarked and followed behind him toward the city of Water Seven, which lay in the latter half of the Grand Line.
It was already close to the Red Line at the end of the Grand Line. Above the Red Line was the Celestial Dragons' Holy Land Marie Geoise, while below it was Marine Headquarters Marineford, guarding the Celestial Dragons' holy land.
In the original story, the old man Venus of the Gorosei slapped the table and told Fleet Admiral Akainu, "The Marines under the World Government are our outer face." Akainu had also retorted to the Gorosei, "Are you being ridden on by the Celestial Dragons too? Have you become their puppets?" Yet those five old men were Celestial Dragons themselves, Imu-sama's representatives, and Imu-sama's puppets as well.
Saint Saturn directly cursed, "Sakazuki, watch your mouth. Don't spout nonsense." Akainu immediately lost his temper after that, then went on to berate Aokiji. With such a powerful Marine Headquarters guarding Mary Geoise, even mighty Fleet Admirals were merely workers in the eyes of the Celestial Dragons. For ordinary people, going up to Mary Geoise was equivalent to seeking death.
Only the Marines had a dedicated naval channel at Mary Geoise. They could first ascend the Red Line and then travel to the Four Seas. The Celestial Dragons also possessed many armed forces in Mary Geoise, the most famous being the CP0 Organization, followed by the Holy Knights of all Celestial Dragons and the God's Guard of the Holy Land.
Pirates, meanwhile, had to take the second route. Beneath the Red Line lay a deep-sea cavern ten thousand meters below the surface, where the fish-men lived, a place called Fish-Man Island. Fish-Man Island had a plant called Oxygen Grass, something Julian's Sky Island lacked. Passing through Fish-Man Island