Xie Xuanyi used modern knowledge to assist the Great Li dynasty for five years, but his outstanding achievements aroused jealousy, and Emperor Jiang Wanying stripped him of his military authority. He staged his own death and planned to spend his days fishing in peace. Little did he expect the Empress of Northern Liang, Tantai Fanyin, to arrive at his door with 100,000 iron cavalry. This rival, who had clashed with him nine times, is willing to entrust him with her military command and national treasury, inviting him to build a new future together. Xie Xuanyi tackles internal and external crises with steelmaking, military training, and political reforms. Meanwhile, a diary reveals who truly deserves the credit for his achievements, prompting Jiang Wanying to regret her actions and head north in pursuit of him. When the two empresses finally meet, which path will he choose?