Synopsis：The film is set in the final years of the Sui Dynasty, when the imperial court is incompetent and tyrannical and turmoil grips the Central Plains. Taking advantage of the chaos, foreign border tribes raid the frontier, slaughter villagers, abduct Han children, and flee through the night. Risking their lives, the villagers light beacon fires to send word, and eighteen elite cavalrymen ride a hundred li to intercept the raiders. They unexpectedly discover that the weapons carried by these foreign bandits were forged using a clay-covered blade-hardening technique unique to the Sui Dynasty. With traitors already infiltrating the court and a massive foreign army pressing in from the border, how will the battle-hardened eighteen elite cavalrymen deliver this crucial intelligence and protect the countless people behind them?