[Clear-headed, beautiful modern doctor x sickly, scheming Grand Secretary x two fake invalids]
While others transmigrate as legitimate daughters who rise to power and take control of the imperial harem, Lin Zhiyu transmigrates into a historical romance after a car accident and becomes Xu Zhiyu, an invisible concubine-born daughter of the prime minister's household who won't survive the opening chapters. When she opens her eyes, the steward is withholding her charcoal, her legitimate younger sister comes to humiliate her, and her former fiance has turned around to climb the social ladder. Everyone is waiting to see when this sickly girl will breathe her last. On the surface, she gasps for breath after every few steps and looks ready to collapse in a breeze. Behind the scenes, she forces the steward to deliver charcoal obediently and leaves her sister speechless. She keeps her skills as a doctoral expert in traditional Chinese medicine under wraps, with her motto being: when the world is in chaos, I'll pretend to be sick first.
An imperial decree suddenly drops, and the emperor bestows her upon Xie Heng, the Grand Secretary. All of the capital slaps their thighs in delight: What a perfect match! A sickly concubine-born daughter and a Grand Secretary with one foot in the grave, two medicine jars together, just waiting to die side by side! The emperor is pleased too, thinking that using a frail concubine-born daughter to keep a powerful official in check is both easy and safe. No one knows that the couple are both skilled actors. Xie Heng's illness is an act. The world says he's half a step from the coffin, but in reality, he schemes in court and is ruthless and decisive. Xu Zhiyu's illness is an act too. Outsiders say she lives on medicine, but in truth, she can cure strange poisons and clear out spies, and her prescriptions are better than those of the Imperial Medical Academy's director. At first, they each play their own role, treating each other with icy politeness on the surface while secretly testing one another with eight hundred schemes. But as they keep acting, things take a turn: he secretly protects her, and she casually adjusts his medicine. Only later do the court officials realize: these two sickly invalids have teamed up to overturn the capital's chessboard!
