Strong theme and atmosphere! I liked this puzzle format (a lot), but frankly, I feel there is a mismatch between the tight time limit and the format of the puzzle: If I want to perform meticulous translation work on books and notes, I want that to be slow and deliberate, not brute-forced due to time constraints. Maybe a different trade-off would have been more effective here.
Additionally: Actions don't always feel like they have an effect: I was quite confused by the safe-combination, since it seemed like I was just booted out of that screen after entering the combination.
However, I can absolutely see a game about a desperate librarian trying to keep it together as the world falls into chaos, decay and darkness around them!