@PonyPon  
I personally would like to believe that it’s a book entitled “How to Spot a Disguised Changeling”.
 
@OtherFritz  
Sounds like the sort of book S1 Twilight would’ve sat down and read cover-to-cover without hesitation. I think she may still do so if she had a enough free time all at once, but she has a lot less of that nowadays, so she’d probably read what she could until something came up.

chrysalis crap! anypony but her

Devious! But a good choice in book.

@OtherFritz  
Sounds a lot like the fanfic I’m writing :q

@OtherFritz  
Fitting for Chrysalis.

@PonyPon  

 
It’s a lengthy novel centred on themes of war, conspiracy, betrayal and vengeance. The story switches perspectives on several occasions, allowing it to convey a great deal of information to the reader. As a result, the worldbuilding is rich and the plot is thick with political intrigue. Some readers might be put off by the somewhat esoteric ideas the book explores, which includes Machiavellianism, Social Darwinism, Authoritarian Hierarchies, Militarism, Imperial Expansion and Collectivism.
 
In short, she’s a good read, if a bit long and appealing mostly to a niche audience. Recommended reading if you have the time, though if a copy appears in your house without you having purchased one, it’s not altogether likely you do.

“I know it’s you. And I cast a spell to formlock you.”

The book is likely a Chrysalis x Twilight fanfic.

And what’s the book about?
 
Does she just change her contents to whatever?

@Background Pony #D8F6  
Lol, perfect! She just has to pretend to be Twilight’s favorite book…
 
 
@Background Pony #BCCC  
Chrysalis is completely unaware that Twilight knows and is going to spray the book profusely with Raid…
 
Either this kills Chrysalis… or she’s immune so long as she stays in book form. In which case she’s trapped.

Chrysalis wanted to blend in with the books. What she didn’t know is that Twilight knows all the books in the library and can see the new one immediately.

The perfect disguise. And if Chrysalis is able to feed off Twi’s love for books, she’ll be unstoppable!