Harry Potter and the Half-Blood Prince

Over and over again, Harry is forced to rely on the help and support of his two best friends, Ron and Hermione. When Ron and Hermione begin bickering, due in part to Hermione's jealousy of Ron's new girlfriend, Harry feels conflicted and upset by the possibility of losing his two companions. Likewise, when Harry develops feelings for Ron's sister, Ginny, he stops himself from taking action too soon lest doing so should jeopardize his friendship with Ron. Even though the three teenagers are getting older, and encountering adult issues for the first time, they ultimately persevere, and at the close of Harry Potter and the Half-Blood Prince, Ron and Hermione vow to accompany Harry on his final quest to destroy Voldemort's Horcruxes and, eventually, Voldemort himself. Harry accepts their offer, having by now learned that he cannot win this battle on his own.

Both Harry and Dumbledore find themselves constantly sacrificing their own peace and happiness for the greater good. Even though Harry would love to assume the life of a normal Hogwarts student, he understands that it is his destiny to fight and destroy Voldemort. Harry is perfectly willing to risk his own life to insure the safety of his friends. When Harry leaves with Dumbledore to collect what they think is a Horcrux, he leaves his vial of Felix Felicis with his friends to protect them should trouble arise. Likewise, Dumbledore is constantly willing to lay himself down to protect Harry and Hogwarts. When Harry and Dumbledore reach the basin containing the locket, Dumbledore drinks goblet after goblet of a poisonous potion, insisting that Harry continue to pour it into his protesting mouth, to retrieve and destroy the Horcrux and a piece of Voldemort's soul.

Harry trusts his best friends without reservation and extends that same loyalty to Dumbledore, following his orders and trusting that Dumbledore is instructing Harry to do the right thing. Harry even tells the Minister of Magic that he is Dumbledore's man through and through. The only issue on which Harry and Dumbledore fundamentally disagree is Dumbledore's insistence that Snape can be trusted. Dumbledore will not tell Harry or any members of the Order of the Phoenix what it is about Snape that makes Dumbledore trust him so unconditionally, but he repeatedly tells Harry that Harry does need to worry about it. At the close of the book, when Snape murders Dumbledore, it is unclear as to whether Dumbledore has asked that Snape complete this task. Either way, Dumbledore has entrusted Snape with his life.

Much of the central action of Harry Potter and the Half-Blood Prince centers on information that is overheard or gathered by covertly following suspicious characters—at Hogwarts and beyond, wizards constantly watch each other. Initially, Harry, Ron, and Hermione follow Draco Malfoy to Borgin and Burkes and then eavesdrop on his conversation with Borgin. Later, Harry has Kreacher and Dobby follow Draco Malfoy as Draco moves around Hogwarts, and Harry constantly uses his Marauder's Map to locate Malfoy when he is on the school grounds. Meanwhile, Tonks appears to be following Harry, popping up unexpectedly whenever it looks like he might be about to get into trouble. Draco Malfoy gets caught by Filch while trying to eavesdrop on or sneak into Slughorn's Christmas party. After Snape drags him off for reprimanding, Harry uses his Invisibility Cloak to listen in on their conversation, confirming his suspicions of Snape.

Lord Voldemort's name is rarely spoken in the Wizarding world, as most wizards are too frightened to let the words slip from their mouths. Instead, they dodge around the issue by calling him “You know who” or “He who shall not be named.” Still, Harry and Dumbledore both regularly say Voldemort out loud, inadvertently expressing their lack of fear and demonstrating their strength in the face of evil. When Harry and Dumbledore use the Pensieve to view Dumbledore's memory from his first meeting with Voldemort as headmaster of Hogwarts, we see Dumbledore only referring to Voldemort by his real name, Tom Riddle. This practice makes the young Voldemort extremely irritated, and he repeatedly requests that Dumbledore not call him Tom. Likewise, when Dumbledore first visits Voldemort at the orphanage, we see Voldemort express extreme distaste for his given name, which he received from his long-lost Muggle father, dubbing it too “common.” Part of Voldemort's hatred of his given name stems from his anger at his father, who left his mother when she was pregnant.

Although Rowling is unclear as to exactly where Severus Snape's allegiances lie, Snape is obviously working as a double agent and is either lying to Dumbledore or lying to Voldemort. This undercurrent of duplicity is consistently present in Harry Potter and the Half-Blood Prince, where nothing is as it seems, and no one is sure who is working for whom. With the Imperius Curse being used frequently, innocent people are often caught committing crimes, and the Ministry continues to imprison guiltless wizards just to give the appearance that they are making progress in the fight against Voldemort. Meanwhile, Draco Malfoy is continuing to pretend that he is a regular Hogwarts student and not carrying out Voldemort's bidding. Even Draco's mother, Narcissa Malfoy, becomes duplicitous, imploring Snape to help her protect her son from Voldemort's vengeance.

The Half-Blood Prince's Potions Book quickly becomes one of Harry's most prized possessions, not only because it helps him so much in Potions class, but because he feels an unspoken connection to its owner. At first, Harry believes that the book may have belonged to his father, and it becomes symbolic of how badly Harry wishes his parents were still alive. Hermione tries to convince Harry that the Prince could be a girl, and then Lupin tells Harry that he never heard James refer to himself as “Prince.” Finally, Harry figures out that the timing is off, and the book could never have belonged to his father. He is devastated. Later, when Harry finds out that the Half-Blood Prince is Snape, he is even more heartbroken.

With the help of Dumbledore's Pensieve, Harry is made privy to various scenes from Voldemort's past. Dumbledore believes that seeing these scenes will help Harry to better understand Voldemort and, consequently, destroy him. While Harry does learn quite a bit about Voldemort's habits and vices, he also starts to understand how difficult Voldemort's life was—like Harry, Voldemort was an orphan and felt that Hogwarts was his only true home. Harry also uses the Pensieve to learn about Voldemort's interest in Horcruxes. Without these memories to sift through, gathered from friends and colleagues of Dumbledore's, Harry would not know how to destroy Voldemort. Once again, Harry is unable to act on his own but must rely on the support and sacrifices of others.

Merope's locket was once owned by Salazar Slytherin and boasts his mark. When Merope is pregnant with Voldemort, she is forced to sell the locket to Borgin and Burkes to get money for food and shelter, but she gets very little money in return, even though the shop owners know that it is nearly priceless. Later, when Voldemort gets a job working for the same shop, he discovers that the locket has been resold to a woman named Hepzibah Smith, whom Voldemort later murders, finally taking the locket back. Dumbledore believes it has been turned into a Horcrux, but when they venture out to collect it, it has already been taken. In many ways, Merope's locket is Voldemort's only remaining connection to his mother and takes on even greater significance than his other Horcruxes. It is appropriate, then, that it is the Horcrux that Dumbledore dies trying to recover.