On their way back from Quidditch practice, Harry and Ron run into Ginny and Dean Thomas kissing in the entranceway to the common room. Something about the scene makes Harry feel sick. Ron starts screaming at Ginny, and she erupts, accusing Ron of never having kissed a girl. Ginny reminds Ron how Harry kissed Cho Chang last year, and how Hermione kissed Victor Krum the year before that. Ron is embarrassed and outraged. Later, Ron asks Harry if he really thinks Hermione kissed Victor Krum, but Harry changes the subject. Harry is worried about the way he is starting to feel about Ginny and tries to assure himself that he’s only being protective of his best friend’s sister. Ron is still angry the next day and ignores Hermione.
Meanwhile Harry keeps trying to boost Ron’s Quidditch confidence before the match against Slytherin, but nothing seems to work. The night before the game, Harry has an idea about how to make Ron lucky. The next morning at breakfast, Harry hands Ron a cup of pumpkin juice, but Hermione notices that Harry is holding a small glass vial in his other hand. Ron drinks the juice, and Hermione, assuming it was Felix Felicis that Harry slipped into Ron’s drink, admonishes Harry. Later, Ron asks Harry if he spiked his pumpkin juice with Felix Felicis. Harry raises his eyebrows and says nothing. The game begins with Gryffindor in an early lead, playing perfectly. Ron saves goals with ease, and Harry catches the Snitch and ends the game. Hermione once again angrily accuses Harry of lacing Ron’s juice with Felix Felicis. Harry explains that he only pretended to spike Ron’s juice, because he knew just the suggestion of luck would be enough to give Ron the confidence he needed. Later, at the Gryffindor celebration, Harry spots Ron kissing Lavender Brown. Harry sees Hermione darting out the door. Harry follows her into an empty classroom, where she is frantically practicing spells and hissing about Ron. Moments later, Ron and Lavender burst into the same room, and Hermione walks out. Harry thinks he hears a sob as she leaves.
Christmas is approaching, and Ron and Hermione continue to fight. Ron insists that Hermione has no right to be angry with him, because she kissed Victor Krum. Meanwhile, Hermione warns Harry that lots of girls are planning on slipping him love potions. Romilda Vane gives Harry a box of Chocolate Cauldrons, which he shoves into his trunk. Harry decides to ask Luna to accompany him to Slughorn’s Christmas party, as friends. Later, Harry, Ron, and Lavender run into Hermione, who announces that she’s attending Slughorn’s party with Cormac McLaggen. Ron is livid. At the party, Harry sees Draco Malfoy being tugged into the room by his ear by Filch, who caught Draco prowling the halls and trying to sneak into Slughorn’s party. Slughorn decides it is OK for Draco to stay, but Snape insists on having a word with Draco in private. Harry slips on the Invisibility Cloak and follows them to an empty classroom, where Snape tells Draco that he must be more careful. Draco is angry and defensive, shouting back at Snape and insisting that he doesn’t need any help. Malfoy storms out, and Snape follows moments later.
Harry and his friends are just beginning to experience the complications that inevitably go along with new romantic relationships. Ron is extraordinarily upset to learn that Hermione has kissed Victor Krum and uses his anger as a mask for his true feelings toward his best friend. Although Rowling never explicitly states Ron’s romantic interest in Hermione, it can easily be inferred from his actions, and even Harry begins to question Ron’s intentions. Rather than confront Hermione about her relationship with Victor, or try to pursue his own relationship with her now that Victor is gone, Ron reacts by simply ignoring her and offering no explanation as to why. His response is immature but effective. Meanwhile, Harry is slowly developing feelings for Ron’s little sister, Ginny Weasley, but he is so insecure about Ron’s reaction that he tries to convince himself that he is simply feeling protective of Ginny. Harry is trying to do the honorable, selfless thing by pretending his feelings for Ginny are nothing more than brotherly. Again, Harry displays his willingness to make sacrifices to ensure the happiness of his best friend.
When Hermione finds out about Ron and Lavender Brown, she is extremely hurt and feels betrayed by Ron. Accordingly, she responds by inviting Cormac McLaggen to Slughorn’s Christmas party. At Hogwarts, as at most schools, the students respond to romantic upset by getting revenge. Just as Ron began a relationship with Lavender Brown to get back at Hermione for kissing Victor Krum, Hermione takes Cormac McLaggen, a boy she can barely stand to be around, to Slughorn’s party, simply because she knows it will upset Ron. Harry feels conflicted about the strange battle currently waging between his two best friends but is distracted by his own issues with Ginny Weasley. Clearly, romance adds a whole new layer of complication to Harry’s school life, one that involves lots of sneaking around, backstabbing, and fibbing. Regardless, the way Harry feels when he thinks of Ginny seems to make up for any uneasiness amongst his best friends.
Even though Harry does not actually slip Ron any of the Felix Felicis potion, the suggestion of luck ultimately proves just as powerful as the potion itself. This episode is an example of how the mind is more powerful than the body, a theme that emerges repeatedly in the Harry Potter series. Dumbledore frequently reminds Harry that it is his heart and his ability to trust and love that protect him from Voldemort, not his physical prowess or magical skill. Ron’s reaction to his supposed dose of Felix Felicis is indicative of just how influential one’s state of mind can be on one’s circumstances. The idea of the power of suggestion comes up again when Harry eavesdrops on Snape and Draco. Even though Harry knows that Snape has been employed as a double agent and needs to lie to Draco to insure that he has further access to Voldemort, Harry’s distrust of both parties leads him to rash conclusions. Certainly the conversation is suspicious, but Harry is so overtaken by his dislike of Snape and Draco that he assumes the very worst from what he overhears.