In the first book Lisbeth was enigmatic with little hints about her life scattered throughout the story so that readers understood there was something more that would explain the complexities of her character. This novel fleshes out much of her back story as we learn more about her past and the influence of events that have shaped her.
Larsson again keeps the action moving, adding layer upon layer to the mystery. He is an excellent storyteller and this book is a definite page turner. Oftentimes in trilogies I find the middle book to be the weakest link, but not so here. This trilogy, as a whole, is compelling and contains no weak links.
The film version is directed by Daniel Alfredson. Michael Nyqvist and Noomi Rapace return to their roles, as do most of the supporting cast. While not as exciting as the first film, the performances are universally excellent. It is helpful to have read the book before seeing the movie to get the most out of it.
See also my review of The Girl with the Dragon Tattoo.