Modern-day doctor Shen Zhiwei opens her eyes to find herself transformed into the so-called plague woman, held at knifepoint on her way to a political marriage. At the wedding banquet, people begin collapsing one after another, each with different symptoms. But she realizes it isn't poison—the water is contaminated. Sealing the well, saving lives, and investigating the water carts, every step she takes threatens someone else's interests. The water someone delivers only gets dirtier the more it is boiled. Someone tears up the list of the dead, while others are desperate to have her sent back to Nanyan to stand trial. All she wants is to save the people right in front of her, but she discovers that behind this outbreak lies an old account no one dares to reopen—and her name happens to be written on the very last page.