Chen Jiu, a soldier from the modern world who has transmigrated into the frontier army, is stationed at a border beacon tower. Amid the chaos of war, he remains true to himself. He unites his fellow soldiers, trains and reorganizes the troops, punishes corrupt elements within the military, and provides relief to displaced civilians. Facing incursions by foreign enemies and power struggles among internal factions, Chen Jiu relies on his intelligence and courage to defend the territory and protect its people. He discovers talented individuals, improves military equipment, and builds a disciplined army. Having endured countless crises and trials, he continues to grow on his path toward defending the borders and ensuring peace for the people.