Orphaned girl Shen Qingyan falls to the bottom of a cliff and accidentally encounters Shan Xun, a red-haired fox demon who sneaks away to eat human jerky and has exhausted his magical powers. The human and the fox make an agreement: the fox helps her practice acupuncture, and she is responsible for providing jerky. With Shan Xun's help, Shen Qingyan learns her family's medical skills and goes out to set up a stall to practice medicine and save lives. Local bullies and the greedy Taoist priest Wang covet the fox demon and wait for opportunities to harm them along the way. To protect Shen Qingyan, Shan Xun burns his vital essence to fight the enemy and is forced by heavenly punishment to return to the heavenly court. Shen Qingyan, who survived the catastrophe, opens a medical clinic to save the world, guards the fox hair, holds expectations in her heart, and quietly waits for Shan Xun's return.