What happened in chapter 18 of bud not buddy?

In chapter 18 of "Bud, Not Buddy," Bud arrives at the library and meets Ms. Thomas, a kind librarian who helps him find more information about his father. He discovers a flyer for Herman E. Calloway and his jazz band, which excites him as he believes Herman may be his father. Bud decides to sneak out of the library at night to find Herman.