The transmigrator Chu Qianqian was ordered by the Xuanling Immortal Sect to go undercover in the Demon Realm. Promised a three-month return date, she was instead treated as an abandoned pawn by the sect and left stranded for three years. By chance, she awakened the Slacker System and obtained a Rejuvenation Pill to wash away the scars on her face. Participating in the Demon Realm Saintess selection, she made her mark and unexpectedly won the appreciation of the Demon Lord Ming Sihan, who had just come out of seclusion. While hiding her identity as an immortal sect undercover agent and maneuvering among her senior martial brothers in the Demon Realm, she completely saw through the hypocrisy of the immortal sect amidst the game between righteousness and evil, choosing her own destiny.