The Yin Iron Spirits have the property of giving their bearers extraordinary abilities. In order to save the spiritual world, the Yin Iron, which has been poisoned by humans, must be found and purified. Since they first met, Lan Wangji and Wei Wuxian have been drawn to each other. Their bond is strong but fate puts them to the test. The burden of saving the spiritual world lies on their shoulders. This is not only about the war of the clans, but also about their love for each other. It remains to be seen whether their bond is stronger than the power of the Yin Iron Spirits.