The Blue Whisper S01 E18 The Secret Chamber

Xue San Yue heads back to Wanhua Valley as she's certain Li Shu only cares about Ms. Qing. She then discovers a secret chamber in Hao Qing's inner hall, and she finds the antidote to Frost Mark in there. While San Yue is chased by Hao Qing for stealing the antidote, Li Shu appears in time to protect her.