There was a study in the house that was left by the Beischel couple. That room was full of books, causing the room to look like a library and not just an ordinary study.
His deceased parents were genius scientists, and they could get the title of genius because they loved to read a lot of books in their life. That was why the room was full of books.
The room was indeed full of books, but Kevin had never touched any of the books on the shelf since seventeen years ago when his parents faked their deaths. Now that they really died, he still didn't want to touch any books on the shelf.
The books were dust-free, though. Kevin hired some maids, and they would clean the room and also the books regularly. That was why the room was still clean today.