Tintin 3 Movie

You've probably heard that Steven Spielberg and Peter Jackson are working on Tintin movie trilogy. So yes, there's going to be a Tintin 3 movie and it is set to be released in 2013. We still don't know who's going to direct the third Tintin movie though: Steven Spielberg is in charge of the first film, Peter Jackson will helm the second, but the director of Tintin 3 hasn't been announced yet. Well, i guess both Peter Jackson and Steven Spielberg will still be involved if not directing themselves.

Jamie Bell and Andy Serkis will of course reprise their roles as Tintin and Captain Haddock.

Nothing about the plot of Tintin has leaked so far. Not even sure there's a script actually... So, if you're fan of Tintin, what comic book of the Tintin series should the movie Tintin 3 be based on? Any suggestion?
:)