Harry Potter and the Half-Blood Prince (Year 6 at Hogwarts)

Opening just a few weeks after the previous book left off, the penultimate entry in the series is, as the author foretold, the darkest and most unsettling yet. The deeds of Voldemort's Death Eaters are spreading even to the Muggle world, which is enshrouded in a mist caused by Dementors draining hope and happiness. Harry, turning 16, leaves for Hogwarts with the promise of private lessons with Dumbledore. No longer a fearful boy living under the stairs, he is clearly a leader and increasingly isolated as rumors spread that he is the Chosen One, the only individual capable of defeating Voldemort.