Wang Mang, a relative by marriage of the Han emperor, overthrows and kills the emperor, ending Han rule. Wu Han’s father dies when he tries to defend the country against the traitor Wang. Imperial censor Ma Cheng takes "the sword of loyalty" to Wu’s mother, Yao, and Ma helps the widow conceal her identity and raise the child. Wang Mang declares himself emperor. When Wu grows up, he is recruited by the new dynasty as a warrior and wins the favor of Wang. The new emperor lets his daughter marry Wu and installs his son-in-law as guardian of an important pass.
Liu Xiu, a royal of the previous dynasty, plans to recapture the government and restore the Han dynasty.Liu is caught by Wu when trying to flee through the pass. Wu excitedly tells his mother about capturing Liu, but she orders him to release his captive and tells him about his father’s death at the hands of Wang. Liu’s mother takes out the “sword of loyalty” her husband earned and orders Wu to help restore the Han dynasty and avenge his father’s death. Wu’s mother also forces her son to kill his wife so as to cut off his connections to Wang. Wu takes his sword and seeks out the princess but finds her praying for him and his mother. Wu finds himself unable to kill such a kind woman. Surprised to see her husband hesitating with a sword in his hand, the princess asks Wu Han about his strange behavior. He tells the truth. The princess seizes the sword and kills herself, and Wu Han’s mother hangs herself. Now that the safety of his mother and wife is no longer at stake, Wu burns his mansion and goes to Liu Xiu to offer his assistance in restoring the Han dynasty.