Harry Potter and the Half-Blood Prince

This year's summer holidays at the Dursleys' are overshadowed by the terror the Dark Lord spreads in both of Harry's worlds: the magical and the non-magical one.
In the magical world Harry himself is known as the Chosen One, the only wizard who might be able to free it from the Dark Lord's terror. Harry avoids this public attention and tries to find out more about the acts of Dark Arts happening in Hogwarts despite the heavy security measures undertaken by Dumbledore in order to protect his students.
The headmaster also shows Harry the secrets of Lord Voldemort's life, especially his youth. With Harry's help he reveals central details of the Dark Lord's immortality.
Besides these private lessons with Dumbledore there is the Half-Blood Prince who helps Harry a lot in one of his worst subjects and makes him receive top grades - planned or not. And who calls himself "Half-Blood Prince" - friend or foe?
At the end of the term many events are turning Hogwarts up-side-down. Harry decides to face the perilous fight against Lord Voldemort openly at last.