They were "scrap metal" selected from the best in the army and thrown into a secret program called "The Furnace". Xia Yan, once the sharpest blade of "Langya", was "exiled" here due to a mission accident. There is no number, no honor, only endless elimination and the task of wandering on the edge of life and death. When the former hero becomes a "loser" and when his teammates have their own agendas, can he reinvent himself in purgatory? When the shadow of international mercenaries shrouded the border, and when the last bullets were loaded, they realized that what was forged in the "melting furnace" was not soldiers, but... Ghosts that shielded the Republic from wind and rain.