A Soldier at the Border, I Rely on Infrastructure to Become a Powerful Minister

Lin Mo, a civil engineer, traveled to Heishiguan, a border pass in Dajing, and became a pawn. Faced with the crisis of five thousand barbarian cavalry about to attack the city, he relied on his professional knowledge to convince Wang Hu of a hundred households, and completed the three-layer city defense transformation of the moat, horse pit, and city wall surface in three days, and also improved the crossbow winch. On the day the transformation was completed, the Hu cavalry arrived ten miles away from Heishiguan, and the war was about to break out.