A fanfic I've heard of has a plot where Hermione accidentally breaks Harry's wand while trying to enhance it with a new spell she's been researching. This leads to a series of comical and yet dangerous situations as they try to reverse the damage without getting in trouble with the Ministry of Magic.
There's a rather unique 'Harry Potter Broken Wand' fanfic where the broken wand gets possessed by a mischievous spirit. This spirit uses the wand's broken state to create chaos in Hogwarts, like making portraits come to life in inappropriate ways or making the staircases go haywire. Harry has to figure out how to exorcise the spirit and repair his wand at the same time.
One fanfic features a broken wand that causes a rift in time. Harry's broken wand somehow messes with the fabric of time, and he finds himself traveling back and forth between different eras of Hogwarts' history. He has to use his wits and the broken pieces of his wand to fix the time rift before the entire wizarding world is thrown into chaos.
The best chapter pointer here is Chapter 5, "Catching Adultery Personally". It opens with Actually, when Manager Fang saw Jiang Li, he was somewhat surprised. and closes on Recently, he did suspect that his wife was cheating on him, but due to the....
Chapter 914, "A Married Daughter is Like Spilled Water!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from Jiang Li let out a cold laugh. to This revelation got the fans even more excited..
Chapter 659, "Bodyguard Agreement", is the clearest early answer because a shaky connection becomes usable in the plot. It opens with Besides, how easy is it to get into the Gu Family? and closes on The woman who had defeated him and taken all his hopes..
Chapter 19 is the strongest chapter-level answer because it starts from What criminal law is this or that, this was originally none of your... and follows through on Please give me Miss Su's birthdate." Mr..
Chapter 762, "Your Son is Even Worse than a Mountain Pig!", is the clearest early answer because it turns Mountain Pig's situation into a concrete plot event. A useful checkpoint is the way the scene starts with The suit was immaculate, and he was very dashing.
Chapter 904, "Welcome Young Master and Young Madam!", is the clearest early answer because it turns Jiang Cheng's situation into a concrete plot event. The chapter turns that into something concrete by moving from Jiang Bufan and Jiang Buchen immediately ran up in surprise.
Chapter 853, "The Bracelet Worn by the Empress?!", is the clearest early answer because it turns Empress Zhaode's situation into a concrete plot event. The chapter turns that into something concrete by moving from Jiang Li carefully examined the branches and leaves for a while.
Chapter 766, "Young Master Gu, Please Come Inside!", is the clearest early answer because it turns Wen Jiaojiao's situation into a concrete plot event.
A practical answer is Chapter 13, because it turns the idea into a concrete scene. The chapter opens with Sensing that something was off with Jiang Yan, Jiang Yan dismissed the..., adds pressure through He probably had a good guess who it was., and ends on How could this happen..." Lin Manru.
Chapter 687, "How Did She Die Again?", is the clearest early answer because it turns Shao Changqing's situation into a concrete plot event. The chapter turns that into something concrete by moving from In the process of pursuing the Protagonist Group, she gradually came... to I'm busy here;