Kaeya usually avoided the domain of the Sumeru Academic but needs must. He had to return the book he had borrowed. And the deadline was today. So, the Cavalry Captain of the Knights of Favonius had braved the Library. At least the Lady Librarian herself was nowhere seen. It wouldn't be a big surprise to find the Dragon Lady who hoarded books napping in some sunlit corner of the library.
The door opened silently, and Kaeya was ready to kiss the maid who most likely maintained the hinges oiled. It was most likely Noelle. He continued creeping in, stepping from the heel to his toes and slowly advancing towards the return station set by the Librarian.
"Oh, Sir Kaeya, it has been a while since I last saw you here," the woman in question appeared behind him. It took most of his willpower not to take his sword out. "Are you here to finally return the book?"
"Dear Master Librarian," the Khaenri'ahn turned, a smile plastered on his face. "How are you today this fine sunny day?"
Lisa just smiled indulgently at the young Captain. Kaeya knew that look. He felt how his neck constricted and he couldn't breathe in. He had to finish his business quickly.
"Indeed. Here it is. Not a stain, not a speck of dirt. And before the deadline!" the last sentence was squeaked as the Sumeru Academic advanced on the man and gently pried it from him to inspect the book for damage.
"Hmm, that is true," she hummed. There was indeed no damage to be observed. She closed the book and gently put it on the cart to return the book later to its place. "But you did make it awfully close to the deadline."
Kaeya swallowed hard. Here it was. Another lecture on the importance of returning books on time. He couldn't really escape without then getting a lecture on the subject from Jean. Which would only result in getting the lecture from Lisa immediately after Jean.
"But you did return it before the deadline," continued the Librarian. "So, I will let you go."
Crisis averted. He wouldn't lose an hour of his life on the lecture on the importance of deadlines in returning the books in pristine condition (which he did) and on time (which he also did).
"Thank you for letting me borrow it, have a great day." Kaeya had managed to escape the clutches of the Dragoness. He might not be that lucky next time. Still smiling, he quickly made his escape but crashed through the doors into one of the knights that were apparently off duty and braving the Library. Both men scrambled to their feet and Kaeya was filled with dread. The knight was sweating and had a shine of hope when his eyes landed on the Captain.
"Ah, Otto. So nice of you to return the book." All that Kaeya could feel was the tiny hairs on his neck standing up. As if the air was full of static electricity. He braved a glance at the Librarian. The air was purple with the charge the Lady Librarian was holding. And she was smiling. Kaeya patted the knight's shoulder who was whimpering before he strategically retreated.
Later, Kaeya would swear that he heard the screams of agony as he climbed the stairs to his office.