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shes been acting all meek and scholarly to make her an unseeming target, having that book would make an evidence of her plotting and scheming ahead and not as passive as she would like this to be. also the watchlist is probably filled with movement records, networks and her other findings not just the initial data she asked nany and father before i think
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I agree with vajavana. While what she's using it for is for investigating and keeping herself safe, without any explicit context written on the book itself, it can be construed as an active effort to manipulate people for malicious purposes. Even if it isn't construed that way it can be used to accuse her of just that if the emperor wishes, and going by his track record and in her understanding and impression of him, he is very likely to do just that if it suits his agenda to punish her with any excuse he can make up.
I don’t understand why him finding the book is that bad, like isn’t it just a list of people she should look out for and who may try to harm her? Wouldn’t that actually help the search for the assassin?? Idk I’m a bit confused on y the emperor getting it is so bad and how much she’s reacting to it