Episode Summary
After Yan Yan goes missing at a banquet, Shen Qilan tries to harm him, but Shen Jiangli intervenes. Lu Jingxiu plots with Shen Qilan against his brother. A "crazy" woman accuses Yan Yan of not being Lu Jingming's son, leading to investigations and Shen Jiangli being confined. Lu Jingming seeks Chu Zimo's help to prove Shen Jiangli's innocence and they uncover a scheme involving switched school uniforms, implicating Shen Qilan.

Spoiler Alert
"My Destined Consort" Episode 21 Recap & Spoilers
So, after that fancy feast, Grandpa Lu wanders off, and poof, Yan Yan is missing! Turns out, little Yan Yan is chilling by the lake, mesmerized by fireflies. Enter Shen Qilan, stage left, looking like she's about to seize an "opportunity." She spots Yan Yan all alone and contemplates chucking him into the lake! Seriously, the drama is already dialed up to eleven.
But wait! Shen Jiangli comes charging in, spotting Shen Qilan holding Yan Yan with seriously sinister intentions. Mama bear is NOT happy. Shen Qilan, now that she's officially the main wife, is dripping with attitude. She throws shade at Lu Jingming, wondering if he's ready to be a dad and questioning if he ever doubted Yan Yan's paternity. Lu Jingming, smooth as ever, shuts her down, declaring Yan Yan is his son, no question.
Meanwhile, Lu Jingxiu is sulking because his brother's life seems all sunshine and rainbows. Shen Qilan, ever the schemer, whispers sweet (and evil) nothings in his ear, hinting that Lu Jingming is about to face some serious trouble. Lu Jingxiu, desperate to one-up his brother, begs her for a plan. Cue evil plotting session!
The next day, while Lu Jingming and Shen Jiangli are taking Yan Yan to meet his tutor, BAM! A crazy lady appears, screaming "Xuan'er!" and mistaking Yan Yan for her own kid, lunging at him. Shen Jiangli shields her son, realizing someone is already trying to mess with her family. Lu Jingming steps up, sword in hand, protecting his family while his men restrain the woman.
The big boss, the Lord of Dong Zhou (Dong Zhou), is thrilled to finally have a grandson, but this paternity drama has him shook. He orders the crazy woman locked up to get to the bottom of things.
Shen Jiangli is now confined to her room, and Yan Yan is temporarily in the care of Lu Jingming's mom. Lu Jingming, finally trusting Shen Jiangli after all these years, reassures her through the closed door that he'll do everything he can to prove their innocence. The feels! They hold hands through the door, a moment of genuine connection.
Lu Jingming remembers that Chu Zimo helped deliver Yan Yan way back when. He rides out to find Chu Zimo, who left the Lu household after Yan Yan's identity was revealed. Hearing about Shen Jiangli's predicament, Chu Zimo joins Lu Jingming to uncover the truth.
Chu Zimo questions the "crazy" woman, who claims her child went missing near a lake six months ago. Spotting inconsistencies in her story, Chu Zimo and Lu Jingming dig deeper. The next day, Lu Jingming brings the woman back, and she immediately hugs a child wearing a school uniform, calling him by name.
Plot twist! It's not Yan Yan! Lu Jingming explains that the woman recognizes the uniform because her own child was wearing one when he disappeared. He reveals that Yan Yan's uniform was tampered with, the tutor confirms the belt was switched! Dun dun dun! Shen Qilan's face drops, and her maid is visibly nervous, trying to hide something. Looks like someone's scheme is about to unravel!