Medical student Lin Wei transmigrates to Chang'an during the Tang Dynasty, where Pei Xuan rescues her when she first finds herself in danger. Pei Xuan, commander of the imperial secret guards, suffers from a chronic illness. Lin Wei uses modern medicine to treat him, and the two gradually fall in love.
Beneath the surface, the great clans of Chang'an are locked in fierce rivalries. The Liu, Cui, Lu, and Wei families each have their own schemes, and Lin Wei is drawn into their conflicts because of her relationship with Pei Xuan, repeatedly falling victim to frame-ups.
Using her medical skills, she opens Huichun Hall in Chang'an, saving lives and healing the wounded. When crises such as epidemics strike, she joins Pei Xuan in fighting the great clans' plots. After countless twists and turns, they foil the alliance's schemes and shake up the old balance of power. In the end, Lin Wei chooses to put down roots in the Tang Empire and stand guard over Chang'an with Pei Xuan, witnessing the rise of a new order among the great clans.
