In J.K. Rowling’s Harry Potter and the Half-Blood Prince (HBP), Professor Snape murders Professor Dumbledore. It appears to be betrayal. However, there is sufficient evidence to prove that it was on Dumbledore’s own orders that Snape killed him. I will first explain how I first came to the idea, and then I will explain why Dumbledore would make such a plan.

To start, I will remind you that Dumbledore was well known to be one of the wisest and most powerful wizards of his time. Therefore, we can believe that his decisions and where he put his trust would have been well thought out. Also, we have seen throughout the books that he knows more than we and Harry do. However, he did say that since he is so clever, his mistakes, however rare, would be even more severe than if he was not, so it is not impossible that he was wrong about Snape, but the point rests that he is usually right.

Also, throughout HBP we are shown Dumbledore’s trust in Snape. Dumbledore is impatient with Harry when Harry mentions his suspicions about Snape. In fact, he is adamant about his trust in Snape and refuses to discuss him any further. I cannot remember another time in the series that Dumbledore acted that way. Furthermore, at the end of the book, after they apparate back to Hogsmeade after Dumbledore was greatly weakened by the potion in the cave, and before they see the dark mark, Dumbledore, despite Harry’s protests, tells Harry to find Snape instead of Madam Pomphrey. So we see that Dumbledore’s trust in Snape is very high, if not above anyone else. Now, we might wonder why this is so, but as we see throughout the series, Dumbledore is aware of Snape’s crimes, including the fact that he told Voldemort of the prophecy, yet Dumbledore trusts him anyway, telling Harry that he felt remorse when he knew that it was Lily and James that would be killed, that his repentance is complete, and that he did something for Dumbledore at high personal risk. We know, therefore, that Dumbledore’s trust in Snape is high if not one-hundred percent.

With that in mind, there is some evidence in the book that led me to believe that there is more to the story than we see.

Our first hint is when Snape is made the Defense Against the Dark Arts teacher. We learn that the position was jinxed by Voldemort so that no teacher would remain in it for more than a year. We learn from this that, until HBP, Dumbledore must have never put Snape in the position for fear he would have to leave the school at the end of the year. He would have two reasons for finally giving Snape the position. First, as the moment is coming for Harry to fight Voldemort, Harry could learn much about Defense Against the Dark Arts from Snape who has more experience in it than most and who knows what Harry must learn in order to defeat Voldemort. It is worth losing a good teacher if it helps Harry on his quest. Lastly, the fact that Dumbledore knew of the jinx implies that he had planned on Snape leaving anyway. With the trust he had in Snape, he wouldn’t risk losing him for any other reason.

Second, as I discussed above, Dumbledore refuses to discuss Snape as if there is something he does not want Harry to know. It is the plan he is hiding of course.

Third, we remember how Hagrid overheard Snape’s argument with Dumbledore:

Possibly, Snape is arguing that he does not want to kill Dumbledore. If he is loyal, then we would know that Dumbledore is the only person alive that trusts him completely and that if he did kill him, he would be mistrusted and hated by his allies. It would be very difficult to be that alone, so it is understandable that Snape wouldn’t want to do it.

Fourth, on the tower, Dumbledore seemed to allow his death to take place. First, when Draco Malfoy came, instead of disarming him, he froze Harry and allowed himself to be disarmed. Apparently, he did not want Harry to interfere. Plus, we know that if Voldemort, as an eleven-year-old with no wand, training, or even knowledge of magic, could use magic to raise a rabbit up and tie it to a rafter that he could not reach, then surely Dumbledore, even without his wand, could have disarmed Draco, who’s hand was shaking.

Furthermore, Dumbledore told Draco that he knew of his plan. He had allowed him to get to this point without interference. Even when the other Death Eaters came, Dumbledore was not afraid. Only when Snape came did Dumbledore show any uncertainty. He seemed to be pleading with Snape. As we know from the first book, Dumbledore believes that death is only the next adventure. Now, he could still fear death because it would give Voldemort freedom. However, I will discuss that later, so let us pretend for the moment that Dumbledore was not afraid to die. He was pleading for Snape to follow the plan. As we know from their argument, Snape did not want to. The only thing that might have interfered with the plan was whether or not Snape would cooperate. We know that Snape possibly could have killed, or at least stunned, all of the Death Eaters around him because he was a very powerful wizard, being the Half-Blood Prince. He could have saved Dumbledore, so we can assume that Snape’s look of revulsion was not aimed at Dumbledore, but like Harry felt when he was giving Dumbledore the potion in the cave, he hated what he was going to do.

Fourth, when Harry was chasing Snape, all the while firing jinxes at him, we hear some things from Snape that are revealing if you think about them. To start, when he is about to reach the gate, he tells the other Death Eaters to leave Harry for Voldemort. This does not say a lot, but he could have jinxed Harry and taken him to Voldemort. Before that, however, we hear Harry call him a coward. Snape shrugs it off, then later, Harry calls him a coward for killing Dumbledore. Snape replies:

If my suspicions about his loyalty are correct, then killing Dumbledore would have been the least cowardly thing Snape had ever done and hearing the person that he was sacrificing himself for call him a coward would have been hard to take in. And even before that, we hear the most revealing thing:

If you read carefully, you will see that Snape had just told Harry how to attack his enemies. He told him to cast his spells nonverbally and to use occlumency. Otherwise, his enemies would be able to hear what spell he had cast or read it from his mind and block it easily like Snape did.

Fifth, and last, whenever a mystery is posed, it is inevitable that it will be revealed. Rowling poses the mystery of why Dumbledore trusted Snape. As we have seen in the earlier books, Rowling tends to twist things. Every time she reveals a mystery, it is something we would not expect. We would expect her to confirm our belief that Snape did deceive Dumbledore. However, that would not be as entertaining as finding out that he is still loyal. Just like when Sirius was revealed to be innocent in PA (Harry Potter and the Prisoner of Azkaban, by JK Rowling) as was Snape in SS (Harry Potter and the Sorcerer’s Stone, by JK Rowling). Moody was a Death Eater and so was Quirrell.

So, after you see the evidence of a plan, it is necessary to know why exactly they would come up with such a plan. To start, we know that only Harry can kill Voldemort. Dumbledore could not, and he knew that, so trying to kill him would be useless. His best bet would be to prepare Harry to do it. The best way to do that would be to tell him how, as he did throughout the book, give him an aid, and give him his independence.

However, one might wonder why he would kill himself when he could be helping Harry find the horcruxes and help him to destroy Voldemort. However, we know that he does not know where they all are. He found and destroyed the ones he could, but the others were nowhere to be found, and the best way to find them would be to have an insider. Snape would be the insider and the only way Snape could prove his loyalty to Voldemort would be to kill Dumbledore. That way, Snape could help Harry find the horcruxes.

Another problem with Dumbledore’s death would be that he is the only person at the time keeping Voldemort at bay. With his death, though we know that the Order of the Phoenix is still active, Snape is in place, and Harry is ready to fight, Voldemort would nevertheless have an open range it would seem. However, as we have seen over and over, even Dumbledore has been outsmarted. Moody, Quirrell, the diary, and even Fudge proved to be problems that even Dumbledore could not solve by himself. So, we wonder why he would sacrifice himself. The answer is found when Harry looks at the locket that was supposed to be the horcrux from the cave. He realizes that the one they found was an ordinary locket with a note inside. The note said that someone by the initials R.A.B. had already taken the horcrux to destroy it. Now, during the cave scene, Dumbledore tells Harry that only a very powerful wizard could reach the horcrux and we see his words come true when he is greatly weakened from the potion he drinks. Therefore, this R.A.B. must have been a powerful wizard. Whether he is still alive or not we do not know, but it is likely that Dumbledore knew him since they were probably Voldemort’s two most formidable opponents. It is possible that either Dumbledore did not know that R.A.B. took the horcrux or that he wanted Harry to see the note for some reason. Either way, we see the possibility that Dumbledore would not be leaving Harry totally on his own.

Also, as we have seen in countless other books and movies, for a hero to be capable of fighting an enemy on his own, he must have already gained his independence. This is apparent in Lucas’ Star Wars, Tolkien’s Lord of the Rings (Frodo never knew that Gandalf came back), Dumas’ Count of Monte Cristo, and countless other works. The hero’s mentor nearly always dies. Therefore, it is likely that Dumbledore realized this problem and knew that he would have to leave Harry at some point for Harry to ever be capable of defeating Voldemort.

Now, we wonder why Snape made the unbreakable vow with Narcissa in the first place if he was not planning to kill Dumbledore just yet. To start, Dumbledore had already ordered him to spy on Voldemort, and refusing Narcissa’s request in front of Bellatrix Lestrange would have blown his cover, in which case, either he would be killed or he would flee. Either path would be a disaster. However, if he made the vow, then he could save Dumbledore while sacrificing himself in the process. It was only after he told Dumbledore about the vow that Dumbledore made the plan.

However, Snape did not seem to be affected by Narcissa’s proposition of the unbreakable vow. We would expect to see some expression on his face or something to reveal how he felt at the time. However, we know from the past books that he is an excellent occlumens as well as legilimens. Becoming an accomplished occlumens requires great emotional control. Therefore, fact that his hand flinched during the vow shows that it was difficult keep calm. And the fact that he was an excellent legilimens shows that he could have read Narcissa’s mind and known what she would say. That way, he could have thought it over before she proposed it.

Lastly, we might wonder why Dumbledore would not tell Harry about the plan. The reason is that Voldemort can read Harry’s mind. As we saw before, they are magically connected, allowing Voldemort to see into Harry’s mind. Also, Snape tells Bellatrix Lestrange that Voldemort is the best legilimens of all time. He would have no trouble finding out that Snape is betraying him. In fact, no one but Snape, who as we know is an excellent occlumens, could know of Dumbledore’s plan without fear of someone finding out. Therefore, only Snape, Dumbledore, and for all we know, R.A.B. knew of the plan.

Now we see that Dumbledore ordered Snape to kill him, knowing that Voldemort still had enough active opponents, so that Snape could then work undercover and help Harry find the horcruxes, and Harry could become independent of Dumbledore, all the while keeping Harry and the Order of the Phoenix in the dark for fear that Snape’s cover might be blown. As you can see, Dumbledore needed to die at the hand of Snape in order for Harry to defeat Voldemort.