One day, a tower appeared in the skies of all the major cities Humans were suddenly summoned to become Walkers, and they needed to clear the tower to save the world. . Floor 77 The Stone of regression was discovered. Walkers could now return to the past. Slowly everyone left. . Humanitys last hope, Carpe Diem was formed, joined by people who refused to abandon the world. . The last Walker reached floor 100. He no longer knew what to believe.