Su Yao is a psychologist who seems calm and composed, but inside, she is haunted by the shadow of her mother's schizophrenia. One day, a patient named Lin Sheng claims he can “see the truth in mirrors” and insists that Su Yao's life is fake. The details he recounts are chilling, as if he has peered into her deepest secrets. As their sessions continue, Su Yao finds strange, inexplicable things happening in her life: her reflection is always a beat behind her movements, photos vanish from her phone, and a mysterious person keeps knocking at her door...
As the boundary between hallucination and reality begins to blur, Su Yao is gripped by unprecedented terror. She must find out who Lin Sheng really is, and whether his “truth” is deranged rambling or an undeniable reality. And with every new wave of fear, she discovers that the version of herself in the mirror is watching her every move...