I am still reading the Magician King as my personal reading book.  I have read a couple new chapters in the book, and things have gotten very interesting.  First, Quentin and Julia did arrive on Earth when Quentin turned the magic key in the air.  Then, while they went their seperate ways, Quentin began to wonder how he and Julia would get back to Fillory.  However, later in the story, they meet up again, and Julia takes Quentin to a house that secretly teaches people magic, and they then use a series of portals to go to Richmond, Virginia because Julia needs to talk to somebody.  So then they take another portal that takes them to Venice, Italy.

When they arrive in Venice, they go to a mansion that Julia's friend have given the address of.  So when they get there, they have to use magic to prove themeselves, so when Quentin breaks a window with magic, they are allowed to enter the mansion.  When they enter, they have to wait for a little bit before they can meet the master of the house.  But when they meet the owner of the mansion, they get a big surprise.  The owner happens to be their old friend from Brakebills, Josh.  So now, they have to involve Josh in their journey back to Fillory, as Quentin and Julia believe Josh could greatly help them get back to Fillory.