He sets Harry the task of convincing Slughorn to give him the true memory so that Dumbledore can confirm his suspicions about Voldemort's rise to power and near-invincibility.
The next morning, Harry, Ron, and Hermione get their Ordinary Wizarding Level (O. Harry is instantly suspicious of Draco, whom he believes to be a Death Eater.
The students return to school, where Dumbledore announces that Snape will be teaching Defence Against the Dark Arts.
On the way, they make a detour to the temporary home of Horace Slughorn, former Potions teacher at Hogwarts, and Harry unwittingly helps persuade Slughorn to return to teach.
Harry and Dumbledore then proceed to the Burrow, where Hermione has already arrived. Later, Ron Weasley and Hermione Granger follow Draco to Dark Arts supplier Borgin and Burkes.
There were many controversies before and after it was published, including the right to read the copies delivered prior to the release date in Canada.
Reception to the novel was generally positive and it won several awards and honours, including the 2006 British Book of the Year award.
Harry learns about Voldemort's family and his foe's evolution into a murderer obsessed not only with power but with gaining eternal life.
Dumbledore shows Harry a memory involving Slughorn conversing with the young Tom Riddle at Hogwarts, which has clearly been tampered with.
As Harry learns more about his great enemy, the love lives of the main characters start to become more active.
Ron and Hermione grow closer together, but after learning from his sister Ginny that Hermione had previously kissed Viktor Krum, Ron shuns her.
Harry's attempts to repair things between the two fail, resulting in Ron going out with Lavender Brown and making Hermione jealous.