The female protagonist transmigrates into a book, learning that she is a fake who took her younger stepsister's place in cultivating immortality. In the original book, her true identity is exposed after eight years, and with her low cultivation level, she is expelled from the sect, ultimately meeting a tragic end with her body and soul destroyed. Reborn and returned, she resolves to cultivate desperately and grow stronger to save her life before her stepsister rises to power. While others sleep, she practices bitterly overnight, accidentally discovering that moonlight can significantly enhance her own cultivation. Along her cultivation journey, she picks up the Demon Lord who was heavily injured and transformed into a little black snake, while mysterious people and exotic beasts burdened with secrets successively gather around her.