Legitimate Poisoning

Half a year ago, my older sister died. The house remains shrouded in a gloomy atmosphere, as if the fire had gone out. While placing flowers before my sister's grave, I apologized. "I'm sorry, Sister... it's taking so long to send those responsible to you." Together with my sister's fiancé, I carry out my revenge. I will make them experience the same pain my sister did. This is the story of how I, a illegitimate child of a marquis household and a maid in the royal palace, fulfilled my revenge.