The book: The Girl With the Dragon Tattoo by Stieg Larsson (No. 1 in the Millennium Trilogy)
The hook: Just as dark and chilling as the icy Swedish setting it takes place in, this thriller follows a disgraced journalist who sets out to solve a decades-old case of a missing girl alongside an unconventially badass computer hacker.
Fear factor: The graphic rape scenes, violence against women, and ominous villains are enough to turn your stomach. But as disturbing as it is, you really can't put it down.