(Joseph has so far been distant and quiet, how and why do you think this changed in chapter 3?
I think that Joseph has changed from being distant and quiet by doing many small things and one big thing, Joseph going onto the bus I think is one of them, calling Jack, Jackie, telling Jack a bit about Maddie (although this didn't happen in chapter 3) and telling his foster family everything that happened. I think that Joseph is acting like this because he realized he can trust his foster family and they may be able to help him find Jupiter.
Why do you think Joseph took the pill the kid offered him that made him attempt to kill his teacher? Do you think they will find Jupiter? What do you think happened to Joseph when he was sent to the school after he attempted to murder the teacher?