A traitor? Me? I’m only four years old!

Jiang Yunsui was originally a spirit mushroom who cultivated awareness in a forest world. When a natural disaster struck, she exhausted her power saving her companions and was reborn by the Heavenly Order into a new world. She awoke as Jiang Yunsui, a four-year-old girl, in the aftermath of a massacre that killed her entire merchant family. During the attack, moonlight and spores healed a fatal wound on her neck, but she fell into a deep coma. She was rescued by Ji Yan’an, the young master of the powerful Ji family, who brought her to his estate in the Northern Desert. Upon waking, Jiang Yunsui learned from the Heavenly Order that she must settle the karmic debts of her new identity by avenging her family’s murder, or she will die at eighteen. Lacking the strength or knowledge to do this alone, she seeks the protection of the most powerful person she can find.

Ji Yan’an is a twelve-year-old military commander who has inherited the Ji family army and its responsibility to guard the Northern Desert. However, he is secretly dying from a slow-acting poison called Phantom Dream, administered by a traitor within his inner circle. The poison causes severe insomnia, hallucinations, and eventual madness. Rival factions within the capital and among his own troops are plotting to seize control of the Ji army while he weakens. Despite his frail condition, Ji Yan’an remains sharp and ruthless, maintaining order through fear and authority. He is surrounded by spies and disloyal servants, making him deeply suspicious of everyone, including the strange little girl who followed him home.

Jiang Yunsui discovers that she possesses a unique ability: when she concentrates on not wanting to be seen, people naturally overlook her presence. This power allows her to move undetected through the heavily guarded estate. After being appointed as Ji Yan’an’s personal maid, she accidentally helps him by exposing two maids who were plotting to poison him further in exchange for becoming concubines. Ji Yan’an realizes her value and decides to keep her close, not out of kindness, but to test her abilities and use her as a spy. In return, he promises to help her find the enemies who killed her family.

The relationship between the two is unconventional. Jiang Yunsui is innocent, food-motivated, and lacks basic human social skills, often confusing Ji Yan’an with her blunt questions and childlike behavior. However, she has a calming effect on him; her presence helps him sleep, which he has been unable to do for years due to the poison. She also inadvertently improves his appetite, as watching her eat joyfully makes him want to eat as well. Ji Yan’an, who has lost hope and grown cynical, finds himself unexpectedly softened by her innocence. Meanwhile, Jiang Yunsui views him as a powerful protector who can help her achieve her goal of revenge.

A physician named Shen Qingzhu arrives and diagnoses Ji Yan’an’s condition, revealing that the poison can be cured with three rare ingredients: the blood of a Phoenix Imitator, the gallbladder of a spirit serpent, and Snow Spirit Grass. However, these ingredients are nearly extinct and located in dangerous, remote regions. The physician can only suppress the poison’s effects for three years. Ji Yan’an decides to use this time to settle his affairs and eliminate his enemies before seeking the cure. He tasks Jiang Yunsui with learning to read and write, though she struggles with the characters. She begins her training while continuing to serve him, navigating the treacherous politics of the Ji estate.

As Jiang Yunsui integrates into the household, she befriends Cook Chen, who cares for her like a mother. She also interacts with Ji Yan’an’s shadow guards, who are initially wary of her but become accustomed to her strange abilities. The story sets the stage for Jiang Yunsui to use her invisibility to gather intelligence on the conspirators within the Ji family and the broader political landscape. Her journey is one of survival and revenge, guided by a boy who is both her protector and her employer. Together, they face internal betrayals and external threats as they strive to secure the future of the Northern Desert.