At the foot of Qingshi Mountain, the orphan siblings Ye Xiaoshuai and Ye Tuantuan make a living by the wild mountains. To grab a full meal, they turn into "little bandits" to waylay and rob people, accidentally running into Xuanchenzi traveling about. The elder brother is an peerless nine-aperture immortal fetus, while the younger sister is a primeval demonic fetus dreaded by all factions. Their constitutions are symbiotic and dependent on each other, while coping with the suspicions of the immortal sects and the plundering of the demonic path. The teenage brother tries his utmost to protect his younger sister, breaks the worldly shackles of immortals and demons, and battles their way out together.