Glaciers melt and land is destroyed, leaving humans to survive only in floating walled cities. Lin Mo, a low-level security guard, accidentally acquires a god-tier grappling hook system. By salvaging ocean debris and exotic beast materials, he can exchange them for food, cultivation methods, and military supplies. After saving a dying traveler and obtaining a heritage map, he awakens the system, fights against the corrupt nobles of the walled city, overthrows the oppressive old order, and repairs and upgrades his safe-haven walled city. He must also deal with threats from sea monsters and pirate forces, and get to know Jiji, the Turing girl. As the countdown for the sea eye to devour the world begins, Lin Mo leads the survivors to break through layer after layer of crisis, striving to set sail towards the legendary only continent.