I read this book forever ago so I will try my best. The main character meets this on girl and walks her to her house. I remember that he used bright world. This means that the girl was pure in heart. I can't remember but if you find the page it is on then you will see words like feather, white, and other words that go along side purity.
I hope this helps! Have a great day!!
P.S When it refers to a house as "fireproof" it means that there are no books in the house.