In the final years of Yong'an, war flares anew across the Sixteen Prefectures of Yan and Yun. Xiao Lie, commander of the Zhenbei Army, has guarded the northern frontier for seventeen years. But just as a hundred thousand barbarian cavalry bear down on the border, he is ambushed from behind by Li Song, a powerful court official. Military pay is withheld, supplies are plundered, and even his subordinate generals are coerced into mutiny. Suddenly, he is trapped between two enemies.
His eldest son, Xiao Cewen, is skilled in both letters and arms. Given a mission in this moment of crisis, he secretly returns to the capital with crucial evidence, hoping to join forces with Prince Jing and tear open the web of schemes woven by the powerful official. But he does not know that the capital has already become a den of danger, where every step puts him on a knife's edge. Meanwhile, Zhao Yan, commander of the personal guard, leads an elite force on a surprise raid behind enemy lines. Through snowy wilderness, they contend with the barbarian shadow guards, striving to cut off the enemy's supply routes and win the front line a chance to survive.
As for Xiao Lie himself, he holds Duanyun Slope with a mere thirty thousand battered troops. Facing an enemy several times their number, he uses his own flesh and blood to shield the northern frontier's last line of defense. Court intrigues and brutal battles collide across the land of Yan and Yun, as the ambitions of barbarian tribes, the treachery of powerful officials, and the fierce loyalty of frontier soldiers intertwine. When duty to the nation meets choices of life and death, and comradeship is tested by political scheming, these people, thrust into the eye of the storm by their era, will ultimately write their own epic of defending the frontier in blood and fire.
