Just Finished Reading The Girl Who Played with Fire

I have just finished reading The Girl Who Played with Fire, which is the second book of the late Swedish writer Stieg Larsson's Millennium trilogy.  As with the first book, The Girl with the Dragon Tattoo, we have the two main characters of Mikael Blomkvist, a journalist and publisher of Millennium, a magazine devoted to exposing scandals for the most part, and Lisbeth Salander, a computer hacking social outcast with a photographic memory.  In the book I just finished, the focus of the story is squarely on Salander while the first book deals mainly with Blomkvist.  Both books expose the scary ease with which the State (at least in Sweden) can declare an individual incompetent and deprive them of their freedom, putting them often under the control of another party who may not have their best interests at heart. This is certainly the case with Salander, whose history of going through the Swedish mental health/social welfare system is described and explained.  Certain facts about her early life seem strangely connected to a double murder (of which she becomes the main suspect) of an investigative journalism team employed by Blomkvist to write a book about international sex trafficking, along with an expose of the same for Millennium magazine.  There is a mysterious individual named Zala who seems to be the key to everything...and this is borne out at the end of the book.  But The Girl Who Played with Fire has a rather strange "ending", even for a book within a series: the story is cut off and the book ended with too many unanswered questions hanging in the air...supposedly to be resolved in the third and final book.  That disappointed me, for I believe that although a series naturally contains a larger story that connects the individual stories, each book within that series should contain a complete story within it (I note that George R.R. Martin totally disregards this in his A Song of Ice and Fire series).  With this second book in Larsson's series, it felt as if the final couple of chapters were simply omitted, leaving me somewhat perplexed.  Will he pick up where he abruptly left off here, or will he pass forward in time to a "new" story in the final book, The Girl Who Kicked the Hornet's Nest?  I shall soon find out...