Chapter 15 of Harry Potter and the Half-Blood Prince: The Unbreakable Vow
As Hogwarts prepares for Christmas, Harry does his best to avoid giggling girls and mistletoe clumps. Ron now spends every evening enmeshed with Lavender Brown who "seemed to regard any moment that she was not kissing Ron as a moment wasted." Ron and Hermione continue to ignore each other, while Harry and Hermione frequently study in the library together. Harry once again has found himself best friends with two people who are not speaking to each other.
Harry has not been able to find a way to avoid Professor Slughorn's Christmas party. Hermione warns Harry that the girls who are infatuated with him might try to slip him a love potion. Asked how a love potion could pass the Secrecy Sensors, Hermione says that the post owl carrying a perfume bottle doesn't know what's in it, so there is no secret to detect. She notes that Romilda Vane is particularly determined to go to Slughorn's party with Harry. When Harry returns to the common room, Romilda is clearly angling for an invitation; rebuffed, she gives him a box of chocolates, which Harry puts away unopened. Hermione suggests that Harry invite someone to discourage the other girls.
Speaking with Hermione, Harry mentions Draco and the necklace again, but Hermione insists the Secrecy Sensors would detect any powerful curse.
Meanwhile, Harry continues doing well in Potions using the Prince's notes. Hermione is still angered that Harry refuses to stop using the Prince's book.
In Transfiguration, Ron accidentally gives himself a handlebar moustache, causing Hermione to laugh. In retaliation, Ron rudely imitates Hermione, sending her running off crying. Harry privately anticipates the upcoming vacation time at the Burrow, hoping the distance will help heal Ron and Hermione's relationship. Harry finds Hermione in a nearby bathroom, being comforted by Luna Lovegood. Hermione collects her things from Harry and leaves.
Luna says that Ron sometimes says funny things, but hurtful ones as well. Harry thinks Luna has a knack for telling unpleasant truths. Luna says she misses the D.A., as she felt she had friends there, and mentions how Ginny sticks up for her and stopped two boys from calling her "Loony." Harry suddenly decides to invite Luna to Slughorn's party—just as friends. Luna is surprised and quite happy, as nobody has ever invited her to a party before.
Peeves has overheard the invitation, and immediately spreads it around the school. Soon, everyone knows Harry has invited Luna. Ron rebukes Harry, telling him he could have asked anyone other than "Loony Lovegood", though Ginny commends Harry. Lavender appears and starts kissing Ron. In response, Hermione loudly tells Parvati that she is going to Slughorn's party with Cormac which causes Ron to resurface from his kiss in shock. Harry ponders the depths to which girls will sink for revenge.
Luna wears silver-spangled robes to the party, eliciting giggles from other girls. Harry, relieved she has foregone her usual Butterbeer-cork necklace and radish earrings, thinks she actually looks quite nice. At the party, Hermione, having escaped Cormac's attempts to get her under the mistletoe, steers Harry and Luna to the refreshments table, where she can watch for Cormac's approach. Snape is also present. When Slughorn comments that Harry is a natural at Potions, just like his mother, Snape responds sarcastically.
Harry is having a great time until Filch drags in Draco, who Filch caught in the hallway, apparently gatecrashing. Slughorn laughingly reprimands him, but allows him to stay, at which Draco looks surprisingly disappointed. When Snape asks Draco for a private word, Harry, hidden under his Invisibility Cloak, follows and eavesdrops on their conversation. Snape probes Malfoy for information about Katie Bell, but Draco mentally blocks him. Snape remarks that Draco's Aunt Bella must have taught him Occlumency. Snape says he knows Draco is working on some project upstairs and offers to help, citing his Unbreakable Vow. Draco says nothing and storms out.
When Harry overhears Snape questioning Draco regarding his secret activities, Snape appears uncertain about the details of Draco's mission, and Draco refuses to divulge anything, even though Snape has sworn an Unbreakable Vow to assist him. However, Draco's refusal to confide in Snape, indicating distrust, does little to convince Harry that Snape is not a Death Eater, despite Dumbledore's repeated assurance that he is loyal. Harry's stubbornness and emotions often overrule his judgment and logic, and his hatred for Snape prevents his considering other possibilities regarding him. It also appears that Harry's suspicions regarding Draco may be correct.
Harry seems oblivious that the opposite sex find him so appealing. His interest in girls has mostly been confined to one person, Cho Chang, and he has seldom considered pursuing other relationships up until now, when he experiences budding feelings for Ginny. That he generally ignores girls who are interested in him may show that he lacks confidence, or that he is so preoccupied by more serious matters that it never occurs to him to seek female companionship other than Hermione or Ginny, his platonic friends. To discourage girls' attention, Harry invites Luna Lovegood to Slughorn's party, partly because he considers her "safe," but he also feels bad that other students mistreat her. Nor has he forgotten her participation in the battle at the Ministry of Magic, in Harry Potter and the Order of the Phoenix, earning her a secure place within his circle. Although Harry knows other students, including Ron, will mock him for inviting "Loony" Luna, he has matured enough that he considers his peers' disapproval is outweighed by one individual's needs. While Hermione and Ginny express their approval, Ron's deplorable behavior not only shows his immaturity, but also insecurity about himself; he shuns the unpopular students, fearing that associating with them will reflect badly on him.
Luna's observation that Ron often says funny things, but also hurtful ones, is accurate and insightful; but considering how Luna risked her own life to help Harry and Ron during the battle at the Ministry of Magic, Ron's rudeness towards her is inexcusable and disgraceful. Ron has previously demonstrated poor behavior not only with Luna, but also Hermione. His difficulty with girls in general, and unresolved feelings for Hermione in particular, results in him lashing out at her for any perceived misstep. After Ginny mentioned that Hermione kissed Viktor Krum the previous year, Ron retaliated by dating Lavender Brown, a rather silly, annoying girl he never particularly liked. Ron's motive largely appears to be to hurt Hermione and make her jealous, without considering how he is unfairly using Lavender, however annoying she might be. Ron may also be trying to prove he is more romantically adept than Ginny claimed; in this, he has made some progress, having finally gotten kissed by someone other than Auntie Muriel, but clearly he remains woefully immature emotionally, and just as clueless about girls. And while Ron's intention may have been to hurt Hermione, in which he does seem to be successful, the silly Lavender's cloying possessiveness may be having an adverse effect on him.
Luna's comments about Ron are interesting because she also tends to say what she is thinking. Whether Luna cultivates her abstract air to soften her comments is unknown. She is correct that Ron tends to disregard others' feelings when he speaks, making what he says painful at times. Curiously, though Luna is often equally direct, her words are not hurtful to others.
Hermione's revelation about Secrecy Sensors having weaknesses indicates it is possible that harmful materials can enter Hogwarts in some circumstances. Whether the cursed necklace that Katie Bell was carrying would have set them off is unknown, as Katie, apparently under the Imperius Curse at that time, was unaware she was transporting something dangerous, and thus no secrecy was immediately involved; Hermione seems to imply that the sensors would still be triggered by the jinx within the necklace, but she is interrupted, and we never learn why she thinks that.
- Why does Harry invite Luna to Slughorn's party? Why does Ron object?
- Why does Ron mock Hermione? Was it deserved?
- Why did Hermione invite Cormac McLaggen rather than another student?
- Is Luna right that Ron sometimes says funny things, but also hurtful ones? Explain. What does Harry think?
- Snape seems to not be aware of what Draco is doing. Yet in the start of this book, he tells Draco's mother that he is aware of the plan. Explain why this is not a contradiction. What does Snape not know about Draco's mission?
- If Snape is magically bound to help Draco accomplish his secret task, why does Draco refuse to confide in him?
Draco's mission has him trying to repair something in the Room of Requirement, which is the place upstairs that Snape is referring to. When Filch caught him "skulking about the halls", Draco was not trying to gatecrash the party; it is only Slughorn's self-centredness that prevents his seeing that Draco has no wish to be there. Almost certainly, Draco was en route to the Room of Requirement to continue with his mission. Likely his vexation with Snape is partially due to Snape's preventing him from reaching the Room for what he had probably hoped would be a productive night's work.
Draco's refusal to accept Snape's help initially seems harder to fathom, as Draco is clearly having difficulty carrying out his mission and probably needs some assistance. Snape has risen quite high in Voldemort's inner council, likely to a level that Draco believes rightfully belongs to his father. Draco has been charged with what he sees as a very important mission, specifically eliminating Dumbledore, "the only one he (Voldemort) ever feared". Draco quite possibly sees this mission as the only means to restore his family to its rightful position, and correctly believes that accepting assistance may help him succeed, but would certainly hinder his family's redemption. He also likely has only Snape's word that there was an Unbreakable Vow, his mother would never have revealed this to him, and he knows Voldemort forbids his Death Eaters from discussing their missions with one another. Add these factors to his own pride and the normal distrust teenagers have toward the older generation, and we can see that Draco's refusal to share his mission details with Snape is completely in character.
Some readers, following the events of Harry Potter and the Order of the Phoenix, suggested that Luna seemed an important enough character that she might join the Trio more completely, possibly even becoming Harry's girlfriend. Events in this chapter both bolster, and deny, that theory; while Harry does take Luna to Slughorn's party, he remains amused by her actions, which strongly suggests the relationship will never grow deeper.
The cauldron cakes that Romilda gives Harry are spiked with love potion, as Hermione had warned. Ron's finding and sampling them will jeopardize his relationship with Lavender, and will result in his accidental poisoning, in the spring.
Related to that incident, we will find that a poisoned bottle of mead had made it into Hogwarts without tripping Filch's Secrecy Sensors. It is unknown how, though it is suggested that because a teacher was carrying the bottle, it was left unscanned; alternately, as the teacher never knew what he was actually carrying, and the poison may not have been magical in nature, the Secrecy Sensors were unable to detect it. It could be argued that as the teacher carrying it was not keeping any secret, the Sensors would not have triggered, and in fact Hermione suggests as much when Harry asks how the girls are managing to get love potions shipped to them. As mentioned, this weakness potentially could result in a cursed object entering the school if the person carrying it was unaware of the curse; however, it is barely possible that the curse itself, being secreted inside the object, would trigger the sensors. Without more information about how the Secrecy Sensors operate, we have no way of knowing, however.
Most of the connections in this chapter, such as Romilda's Chocolate Cauldrons, Katie Bell and the cursed necklace, and Professor Snape's unbreakable vow, are to events that happen in this book.