This work is produced with AI assistance. Zhu Xiaosheng brings sand-print samples back to the foundry, wanting to use precision technology to improve traditional dry molds, but is questioned by Master Zhu. Apprentice A Tie repeatedly collapses sand molds, and through repeated comparisons and trial castings, he gradually understands that digital precision cannot replace sand mold feel and casting experience. Su Xiaozhu assists in recording the process, while Old Lutou guards the furnace fire. In the end, Master Zhu hands the dry mold over to Zhu Xiaosheng to cast personally, and after molten iron enters the mold, the casting succeeds. A new generation of artisans learns reverence from failure, and master and apprentice jointly deepen their understanding of the relationship between manual work and technology.