Anyway, the story centers on an unassuming warrior played by Andy Lau. A city in the path of an army seeking to invade another kingdom is fearful of being swallowed up in the process, as the Zhao forces need to protect their rear and maintain a secure supply line. Therefore, the city seeks aid from the Mozi clan, famed for their defensive expertise.

It later turns out the lone hero who comes to their aid did so on his own conscience, as the Mozi clan actually did not want to get involved.

None the less, although he is not a veteran general who had never protected a city before, he convinces the local king to trust him as their only hope, and he is granted command of the garrison. Naturally, his skillful tactics and leadership stymie the enemy and force them to withdraw. It indeed becomes a "battle of wits" as the opposing general becomes obsessed with defeating this Mozi military genius, to the point of abandoning his original invasion of the other kingdom.

However, there's more to the plot than that. The success of the Mozi warrior breeds jealousy and resentment among the city's elite, and his popularity among the people and his preaching of "universal love" threatens the king's autocratic rule. Therefore, he is ultimately betrayed and arrested by the very people he risked his life to defend, only to escape with a little help.

In the meantime, the Zhaos prepare one last sneak attack, and it really amounts to a test by their general to see if this brilliant warrior is really so pure that he would return to again save the city that had forsaken him.

Although the story is inspired by the Era of Warring States prior to China's unification, the movie's creators do take some strange liberties. For example, Andy Lau's character rescues a Mandarin speaking black guy (how did an "African" fellow end up in 4th century BC China?), and there is a battle sequence where the Zhaos attack with from the sky via hot-air balloons, which looks rather corny to me.

None the less, aside from these fanciful elements, it's a fairly well told story of sacrifice, loyalty, honor, and the quest for peace in a troubled world.