Chapter 25 of Harry Potter and the Half-Blood Prince: The Seer Overheard
Harry and Ginny are happy together, laughing over the circulating rumors about them; for once, everyone talking about Harry actually makes him happy. Ron and Hermione seem to be growing closer as well, and Harry's concerns that his and Ginny's relationship could affect his friendship with Ron have largely evaporated.
Harry dares not enter the Room of Requirement to recover his Potions textbook, worried that Snape might confiscate it. As a result, his Potions work is suffering, though Professor Slughorn attributes this to his relationship with Ginny. Hermione, meanwhile, theorizes about the 'Half-Blood Prince'. A write-up she found about a former Hogwarts student named Eileen Prince, suggests that if she was a half-blood, she could have been the "Prince".
When Harry is summoned to Dumbledore's office, he encounters Professor Trelawney sprawled on the hallway floor, outside the Room of Requirement. She admits to using the Room of Requirement to hide her sherry stock, but she is unable to get in. Harry thinks the 'whooping' she heard from within is Malfoy finally finishing his task. When Trelawney called out in the darkness to see who was there, she was pushed out into the hall. Harry suggests she tell Dumbledore. Trelawney accompanies him, and along the way, she recounts the evening that Dumbledore hired her. When she mentions that Severus Snape had interrupted their interview, Harry realizes that he was the one who passed the prophecy to Voldemort, resulting in his parents' deaths.
After a fiery exchange with Harry about Trelawney's revelation, Dumbledore simply states he has reason to trust Snape, despite Snape's skills at Occlumency. Dumbledore has located another Horcrux, and if Harry wishes to accompany him to retrieve it, he must follow Dumbledore's instructions explicitly. Harry promises, and Dumbledore orders him to fetch his Invisibility Cloak and meet him in the Entrance Hall.
Before leaving the castle, Harry gives Ron and Hermione his Marauder's Map and the phial of Felix Felicis potion, believing there could be some imminent danger now that Draco has finished his task. Harry tells Ron, Hermione, and Ginny to use Felix to protect themselves, and wants Dumbledore's Army to guard the Room of Requirement and also Snape.
Harry and Ginny are happy, finally realizing they were meant to be together. However, their happiness may be short-lived: the book's mood is rapidly becoming markedly darker, especially when Harry learns it was Snape who betrayed his parents. Also, Harry knows that whatever task Draco has been working on appears to be completed. Just what this task is and how it will affect Hogwarts is still unknown, and Harry is exceedingly frustrated that his warnings about Draco's suspicious activities have been repeatedly ignored by Ron and Hermione, and apparently also by Dumbledore. However, it is actually unlikely that Dumbledore ever ignored Harry's warnings, and he likely knows what has been happening within his own school. Harry fails to realize that a Headmaster is unable to divulge sensitive information to a student, even Harry. There have been hints that Dumbledore assigned Snape to investigate Draco's suspicious behavior. And while Harry continues to suspect Snape, Dumbledore reiterates his complete trust in him.
Many story lines in this book are rapidly coming to a peak in this chapter. It was Trelawney's prophecy that was conveyed to Voldemort, while Draco has apparently completed a major portion of his mission. Also, Dumbledore is preparing to leave the school with Harry to hunt down another Horcrux. Because Draco's task has apparently reached this point, Harry fears that the the Order of the Phoenix guards patrolling are now insufficient. They are only guarding the school's perimeter and the known entrances into Hogwarts; Harry suspects the threat is Draco, and also Snape, from inside the Room of Requirement. His instructions to Ron and Hermione are based on that suspicion.
At least one reader has commented that Madam Rosmerta is acting out-of-character in this chapter when she is seen tossing out an unruly customer: we have been led to believe that she generally runs an orderly pub, and should not have to resort to physically ejecting wizards, and yet she is seen doing exactly that. Of course, we have never been in Hogsmeade during the evening, so we have no idea what generally goes on then.
- What exactly did Snape hear when Trelawney related the prophecy to Dumbledore?
- What might have Snape done or said that has made Dumbledore trust him implicitly?
- Why did Dumbledore never tell Harry who overheard the prophecy?
- Why were Harry's repeated warnings about Draco Malfoy continually ignored, especially considering Malfoy's obviously suspicious behavior?
We have the clue needed to determine why Harry was unable to enter the Room of Requirement while Draco was working in there, and Harry has the option of going in and finding out what Draco has been doing. Trelawney reveals she was hiding her sherry in the Room, which was in the same warehouse form as when Draco was using it. We can guess that the invocation, "I need some place to hide my sherry," caused the junk warehouse to appear, which was the same form as when Harry hid his Potions book there in the previous chapter. It is likely that whatever Draco is working on is inside that warehouse. The other revelations that Trelawney revealed, however, are profound enough that he, and we, failed to notice this clue.
It is interesting to note that after this book's publication and before Harry Potter and the Deathly Hallows was released, many "good Snape" theorists based their opinions on Professor Trelawney's identifying Professor Snape as the intruder the night she gave the prophecy. Since we know from Chapter 16: Professor Trelawney's Prediction in Harry Potter and the Prisoner of Azkaban that Trelawney is oblivious to her surroundings while experiencing a true prophecy, she could only have seen Snape before or after she related the prophecy to Dumbledore. This contradicts Dumbledore's story that the intruder (Snape) only heard the prophecy's first half before being ejected from the Hog's Head Inn. Furthermore, since we know from Voldemort's actions in Harry Potter and the Order of the Phoenix that Snape only heard the prophecy's first half, many people assume that Snape either heard the entire prophecy or none, and either way, only reported as much of it to Voldemort as Dumbledore ordered him to. This would certainly go a long way towards explaining why Dumbledore trusts Snape. However, it is also necessary to remember that in both instances, Trelawney repeated the prophecy's beginning. Therefore, the prophecy's critical part was the middle. If Snape heard only the end, and relayed that to Voldemort, that would be the same as carrying only the beginning.
Later information leads us to believe that Snape was Voldemort's ally, but after sharing the prophecy's content, he was revolted by how Voldemort utilized this information. In Harry Potter and the Deathly Hallows it is learned that Lily Evans was Snape's great unrequited love, and so when Voldemort determined that the prophecy meant that she and her child (Harry) must die, Snape was effectively lost to the Death Eaters.
Snape's memories in that chapter suggested that Dumbledore never ignored Harry's information about Draco and Snape; his response to Harry was always, "Put that out of your mind." Literally, he was saying that this was not Harry's concern, not that it was unimportant. In Snape's memories, Dumbledore already knew about Draco's mission before Snape told him, and before this book had even opened, though we never know how he learned this. (Dumbledore and Snape talk of Draco's mission when Snape has just finished containing the curse which killed Dumbledore's hand; and the damage to his hand is alluded to in chapters 2 and 3 of the book.) So Dumbledore's response to Harry's information is more along the lines of, "I already know all about this, and you should not concern yourself with it." Dumbledore had said previously that he is an old man, and old men tend to forget how young men think and feel. Perhaps dismissing Harry's concerns this way is another case of this forgetfulness?
Hermione's belief that Eileen Prince could have been the Half-Blood Prince is incorrect, but her theory is actually closer to being accurate than she, or anyone, realizes.
Madam Rosmerta's greeting Dumbledore in passing is more important than it seems. We shortly discover that she is under Draco Malfoy's control, which may account for her uncharacteristic aggressive behavior when she ejects a customer from her establishment. It was because she was under Draco's control that she sent the poisoned mead and the cursed necklace to the school, in an attempt to kill Dumbledore. Tonight, when Rosmerta sees that Dumbledore has left Hogwarts, she notifies Draco, who uses this opportunity to allow Death Eaters into the school through the Vanishing Cabinet.