The first thing that came to my mind was that he was an assassin after Shizune, because of all the people in the library right now, she had the most important identity. I knew this was no time to hesitate, so I punched him in the chest with all my strength and pushed him away.
The man regained his balance after being thrown back a few meters between the shelves and that's when I saw the dagger in his hand emerging from his black camouflage. When I saw a liquid dripping from the tip of the dagger on the floor and the smile on the man's face, which appeared for a moment and then disappeared again due to the impact of my punch, I realized that something was wrong and I saw the cut mark on his fist which caused me to feel a slight pain.
Apparently I had been poisoned...