AO3 is a great resource. Just type in 'Snape the Spy' in the search bar, and you'll get a bunch of relevant fanfictions. Another option is Wattpad. While it has a more diverse range of content, there are still some interesting Snape - the - spy fanfictions to be found. You might also want to check out some Harry Potter fanfiction forums. Sometimes, fans share their own works or recommend good ones there.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of Harry Potter fanfictions, including many that focus on Snape as a spy. Fanfiction.net is also a good place. There are often dedicated sections for Harry Potter fanfiction, and you can search specifically for Snape - centric spy stories.
The best chapter pointer here is Chapter 83, "Can Actually Carve Flowers?!". It opens with When they received the task, the three of them were already sharpening... and closes on Since all the guests were staying at Uncle Zhao's cabin, Director Sun....
Chapter 26 is the strongest chapter-level answer because it starts from Shen Lan was bent over processing a large stack of press briefs on her... and follows through on If you think you can use our family connection to have me handle this....
The best chapter pointer here is Chapter 44, "Laozi's Hands Are Made to Drive a Ferrari!". It opens with But the next move by the production team proved they hadn't forgotten the... and closes on Does anyone here know how to drive?.
Chapter 73 is the strongest chapter-level answer because it starts from Director Sun, tongue-tied, finally managed to squeeze out a sentence,... and follows through on Despite Wen Jiaojiao's fiery temper, there were still many who were drawn....
A practical answer is Chapter 71, because it turns the idea into a concrete scene. The chapter opens with Shu Yan curled her lips with a hint of jealousy, "When can it be my turn..., adds pressure through The sun is so intense;
A practical answer is Chapter 90, because it turns the idea into a concrete scene. The chapter opens with Watching He Yun gradually take control of a tractor under professional..., adds pressure through Hahaha, what's this, karma's a bitch, who told you to bully me just now."..., and ends on Jiang.
If you want the clearest chapter reference, go to Chapter 26. Early on, Shen Lan was bent over processing a large stack of press briefs on her...; later, the chapter leans on She was nearly forty years old, but because she took good care of herself....
If you want the clearest chapter reference, go to Chapter 47. Early on, Qi is actually second???] [Did the production team make a mistake?; later, the chapter leans on Isn't Qi supposed to be first?] [So who's first?.
Look to Chapter 49 for the clearest answer. It begins with My phone!!!" Jiang Yan's roar echoed continuously through the mountains in..., keeps building through Watching helplessly as his latest-model phone was taken away by a..., and lands on Thinking this, Jiang Yan marched forward, pulled Jiang.
Chapter 44 is the strongest chapter-level answer because it starts from But the next move by the production team proved they hadn't forgotten the... and follows through on Does anyone here know how to drive?.