In his past life, he was an engineering supervisor whose signature was on the blueprints, taking the fall for someone else and ending up in a police station, watching helplessly as his daughter fell ill and his home was destroyed. Waking up, he is reborn back onto the construction site in 1998, becoming a manual laborer publicly humiliated by the foreman. These steel bars are HPB235, which cannot be used for load-bearing pillars. With a single sentence, he reports the grade, leaves them for three days, and when they collapse, the whole scene falls silent. From then on, he taps bricks to recognize them, figures out mortar mix ratios with a single twist, and publicly shovels down walls built with cut corners; when an old factory building is left untouched by anyone, he knocks on walls to inspect beams, draws blueprints on cardboard to report construction costs, and wins his first order.