Percy recalled at some point that Theo had said he had his library here. And whilst the two of them hadn't actually spoken in person yet, there was no harming in making that acquaintance in aforementioned library. Plus, Percy really needed to look some things up, and whilst the library the hotel provided was pretty good, there was always something to be said about personal libraries. Family libraries. As a child he had always run off to explore the libraries of his parents friends. It may explain why he didn't have a lot of his own friends as children, but he had loved seeing the old tomes and ornate books that had made their way into a collection.
He held personal libraries to a high standard, but even then he was pleasantly surprised when he stepped inside, knocking on the ajar door to announce his arrival. It was definitely a wow. And there were always bonus points if one had to tip ones head back enough to ache to see the top rows of shelves.
Percy was excited, and his fingers itched to start looking around. Aside from his knock he'd now completely forgotten about making himself known, or about anything aside from how many things he could learn in here.
So many. So very many.
He reached the first shelf of books and started to read along the spines. He didn't know a lot about magic, but even those books were fascinating to him.