Ender’s Shadow and The Movie
I just read Ender’s Shadow and I wish I had read it immediately after Ender’s Game. It is excellent. And I just found out there will be a movie that combines both books!
If you haven’t read the books, do it. And skip Speaker for the dead and the other books in that series. Go straight from Game to Shadow. Trust me. You can always go back to Speaker (though it’s probably not worth it).
Game and Shadow take place in the same timeframe at the same time but have different main characters. Think of them as the same book with two parts.