In which episode of Heroes, Ji Fa cut off the dragon's head?

Jiang Ziya cured the Buji plague. Zhou Wang learned that his army was wiped out and blamed the Buddhists. Su Daji excused Buddhists and put the blame on Jiang Ziya. It happened that the East China Sea tribe rebelled and took the opportunity to hold Master Wen. Nu Wa Niangniang sent the Dragon God to Xiqi for rain, but she met Hu Xianer and Qing Qing on the way. Qingqing's plan to persuade the Dragon God to flood Xiqiao with rain was seen through by the Dragon God, and Hu Xianer was prepared to poison Xiqiao when the Dragon God distributed rain. Xibohou divination divination, the dragon god predicted divination forward. Because Xibohou's divination was accurate, the dragon god felt ashamed. Hu Xianer and Qing Qing persuaded the Dragon God to change the rain order of Nu Wa Niangniang, wiped out Xiqi by the hand of the Dragon God, and poisoned the rain. The next day, according to Xibohou's divination, it began to rain. Sanyisheng took this opportunity to ask Xibohou to send troops to crusade against Zhou Wang. Xibohou loves the people and can't bear to fight, so as not to make the people miserable. Sanyisheng was deeply impressed by Xibohou's benevolence and righteousness. At this time, the servant heard that the rain in Xiqiao continued unabated, and many people died unexpectedly after being caught in the rain. Jiang Ziya saw the poisonous rain endangering the people and ordered Zhao Di and Wu Ji to make an antidote to detoxify the people. Hu Xianer and Qing Qing came to Jiang Ziya's hut and attacked Jiang Ziya. Jiang Ziya was in danger and told Hu Xianer that he was the first person to own Nuwa Stone, which made Hu Xianer hesitate. Qingqing was injured by Jiang Ziya's whip. Wu Ji took his mother to avoid the poisonous rain and was stopped by Shen and Yuqing. Nezha came to fight with Shen. Xibohou learned that the people were suffering from floods, and he was very painful. He advocated opening a granary for disaster relief, but regretted his divination.