Modern soldier Shen Lie unexpectedly arrives at the frontier of the Great Yu dynasty. Faced with hardship and oppression, he refuses to give in. Relying on his exceptional skills and strong sense of responsibility, he rises from an ordinary frontier soldier to a commander who protects the region. He rescues the fallen empress Ji Minghuang, who is living under the assumed name Agu Duo, and respects her choices and dignity. Through adversity, they learn to trust and support each other. Shen Lie unites his comrades, improves the defenses, and enforces strict military discipline. Leading the soldiers and civilians of Heihe Fort, he repels incursions and protects the people, ensuring that the troops have enough food and warm clothing while their families can live securely and farm their own land. In the face of enemies and trials, he always puts the people's safety first, defending the frontier with courage, wisdom, and unity while honoring his promises to his country, his comrades, and the woman he loves.