On the night of the full moon, Nian, a weak scholar hurrying to the capital for the exam, is tripped over by a bone in the Black Mountain Woods. He turns to see a white fox staring at him, and frantically climbs up to flee this eerie forest. While being chased by the fox demon Xiaoqian, Nian encounters the heavily wounded deputy general of the Imperial Guard. Coincidentally, the demon hunter Yan Chiluo arrives and saves them both. Nian helps the injured man up and hides in Lanruo Temple. Knowing he is dying, the deputy general writes a blood letter entrusting Nian to deliver it to Zhuge Jing, the leader of the Black Mountain City Imperial Guard. After Yan Chiluo drives away Xiaoqian, he leaves Nian a scripture and departs. Xiaoqian is injured and reports back to Ah Huai, who orders Xiaoqian to obtain the pure heart of the scholar Nian. Nian arrives at the Imperial Guard seeking Zhuge. While being shoved by the Constable at the gate, the scripture given by Yan Chiluo falls out, attracting the attention of Master Qiu, a disciple of the Kunlun Sect. With Master Qiu's help, Nian sneaks into the Imperial Guard and hands the blood letter to Zhuge Jing. However, Nian is imprisoned for trespassing. Zhuge orders Nian to find the deputy general's body to atone for his crime. Nian returns to his residence, and a painting of a stunningly beautiful woman suddenly floats in. Xiaoqian in the painting is sitting by the window, watching him...
