My wife and I saw the movie "The Girl With the Dragon Tattoo" without first reading the book. We then got a copy of the second book in that mystery trilogy, "The Girl Who Played With Fire," and have been intensely absorbed in it ever since (Roberta has completed the gripping tale; I'm halfway through), just as several millions of others around the world have been. You seldom will find a similar book as hard to put down, as novel and nutty.
Unlike "The Girl With the Dragon Tattoo," set mainly in the countryside of Sweden, "The Girl Who Played With Fire" is almost wholly set in Stockholm, to which I've been on numerous occasions, once accompanied by Roberta. It's a tremendous kick to recall the various geographic references to the streets and sections of the Swedish capital, and to the sophisticated life of that prosperous place. The way to best enjoy your stay is to pester friends in advance of going there for the names of anyone they know who lives in Stockholm. We did that on our last trip, and arranged to have dinner on two occasions with English-speaking residents of Stockholm, in Stockholm. The Swedes, I can tell you, get a big kick out of foreigners' curiosity about the social structure and economic system of Sweden. One couple brought with them a sheaf of statistics to the dinner we had arranged in a Stockholm restaurant, and were able to quote chapter and verse as I quizzed them about income, wages, taxes and Swedish social benefits.
According, however, to the mystery trilogy that began with "The Girl With the Dragon Tattoo," by the late Stieg Larsson, life in Sweden isn't all comfort and calm; there's a large police force constantly in combat with various criminal gangs, such as traffickers in Eastern European women brought there to engage in prostitution (the main theme of "The Girl Who Played With Fire"). There also is a tolerance, apparently, for the most outre of sexual practices, which also are vividly portrayed in "The Girl Who Played With Fire" (probably a reason for the immense, worldwide-best-seller status of these books, sold by the millions of copies).
But even on a straight touristic level, you'll enjoy the description of Stockholm, and if you haven't been there, you're missing an experience in one of the most unusual cities (and countries). Don't fail to visit the bookstore of The Swedish Institute, in the heart of Stockholm, which sells all sorts of pamphlets and paperbound books explaining the society of Sweden to the curious foreigner (I usually return home with a pile of those interesting presentations).
Again on a contrary note, the late Stieg Larsson, who wrote these monumental best-sellers (he died of a heart attack before he could learn of the worldwide success of his books), was an editor of a leading Swedish magazine who earlier had become an expert, as the book advises you, on "antidemocratic, right-wing extremist and Nazi organizations." With all its prosperity and perfectly functioning democracy, Sweden is not immune to having to deal with extremist political groups, which is a puzzling but interesting phenomenon.
You probably already have picked up a copy or two of these books that now lead the fiction best-seller lists. But in addition to reading about Stockholm and Sweden, you really should go there.