This was a rewrite of the post I did a bit ago.
A few quick notes:
All page numbers are American hardcover editions.
I have shorthanded the books this way:
Stone
Chamber
Prisoner
Goblet
Phoenix
Prince
I’ll start with a timeline:
Spring/Summer* of 1980~ The prophecy is made. Voldemort is told about it by Snape.
(I'm guessing on the season since Dumbledore said it was shortly before Harry's birth. (Phoenix, PG 839))
July 31, 1980~ Harry Potter is born
August 1980*-January 1981~ Harry Potter's christening, the Potters go into hiding
(We know that at the time of Harry's christening, the Potters were already in hiding. Children are *usually* I believe, christened in the first six months of their lives, hence the 6 month window for this event.)
July 31, 1981~ Harry's first birthday
October 31, 1981~ Voldemort murders the Potters
September* 1981~ Snape takes up the post of Potions master after applying first for Defense Against the Dark Arts.
(Snape said in October of Phoenix (PG 363) that he had been potions master for 14 years. I am assuming that he gave Umbridge an accurate number. However, we can't really assume that he meant 14 years down to the month. So I just put that he started at the beginning of the year. We know for sure he was hired in 1981. I am inclined to believe that he was hired around the time the Potters were killed, because I very much doubt that the timeframe in which these things occurred can be a coincidence. )
Okay, now that that is a bit clearer, let's examine this. First off, that is quite a long window between when Voldemort first learned of the prophecy, and when he succeeded in finding the Potters. It's about the same amount of time it took him to find and kill Karkaroff. (Prince, PG 106) So I'm going to speculate that Karkaroff, having no one we know who would be his secret keeper, was not protected by the fidelius charm. So let's assume that a person using methods other than the fidelius charm to hide from Voldy, will wind up dead in around a year. (Yes, I am aware that Regulus was killed in three days, but I believe he, not Karkaroff, is the exception. But that's a whole different topic.) From this, I gather that the Potters were in hiding from the time Harry was born. When the threat of Voldemort started to grow, they decided to use the fidelius charm. All of this means two things: Voldemort chose to kill Harry almost as soon as he heard the prophecy, and Dumbledore knew it. This seems likely to me. I doubt Voldemort would be the type to forget people who have defied him, and Lily and James had defied him three time. Also, since he is a blood fanatic, he would know that Lily was muggle born. He had the information Dumbledore said he used to choose Harry right from the beginning, so there is no reason to believe, in my opinion, that he did not make his choice immediately.
This brings us to another question: How did Dumbledore know who Voldemort was after? In Prisoner (pg 204), Harry hears Fudge say:
"Not many people are aware that the Potters knew You-Know-Who was after them. Dumbledore, who was of course working tirelessly against You-Know-Who, had a number of useful spies. One of them tipped him off, and he alerted James and Lily at once. He advised them to go into hiding. Well, of course, You-Know-Who wasn't an easy person to hide from. Dumbledore told them that their best chance was the Fidelius Charm."
Now Fudge makes it sound as though the Potters performed the Fidelius Charm immediately. But I don't think so. If that were true, wouldn't they have been killed much sooner? Wormtail would have turned them in then. Why would he have waited more than a year? No, since we have evidence that people can hide from Voldemort for a year, I don't think they were under the Fidelius immediately. Plus, this is Fudge, not exactly your reliable source of information. But let's look at what else he said. He says Dumbledore had "a number of useful spies." Now that's interesting. The only Order spies we know of are Snape and Lupin. I very much doubt Lupin would have found out anything useful from werewolves, so let's look at Snape. From what we know so far, the logical conclusion is that Snape told Dumbledore that Voldemort was after the Potters. This means that between the spring of 1980, or whenever the prophecy was made, and the time the Potters went into hiding, Snape changed sides (supposedly). He became a spy, anyway. What would have caused him to do this? Dumbledore says in Prince (pg 549):
"You have no idea the remorse Professor Snape felt when he realized how Lord Voldemort had interpreted the prophecy, Harry. I believe it to be the greatest regret of his life and the reason that he returned--"
That is very interesting, because if it is true that this was the reason Snape changed sides, and that Snape told Dumbledore that Voldemort was after the Potters, then that means that 1) Snape changed sides before the Potters died, presumably to save them. 2) Snape had reasons for saving at least one of the Potters. The idea that Snape changed sides before the Potter's death makes sense, because he started teaching in 1981, the year of their death. Obviously Dumbledore would not have given him the job unless he had a reason to trust him. THE reason to trust him, in fact. The reason he changed sides before the Potters died. Let's look at this. Assuming Snape did tell Dumbledore that Voldemort was after the Potters, then he must have cared for at least one member of the Potter family. According to Dumbledore, he only regretted his decision to tell Voldemort about the prophecy AFTER he found out how Voldy had interpreted it. So he was not opposed to Voldy murdering a family as such, it had something to do with the PARTICULAR family. So, whom in the Potter family would Snape not want dead? He didn't even know Harry, so I think we can rule him out. So we're left with James and Lily. Interesting. Consider this conversation from Prince (pg 616):
Harry: "Snape passed Voldemort the information that made Voldemort hunt down my mum and dad. Then Snape told Dumbledore he hadn't realized what he was doing, he was really sorry he'd done it, sorry that they were dead."
Lupin: "And Dumbledore believed that? Dumbledore believed Snape was sorry James was dead? Snape hated James..."
Harry: "And he didn't think my mother was worth a damn either, because she was muggle born.... 'Mudblood,' he called her...."
It's interesting that Harry is the only person who says that Snape hated Lily. Lupin doesn't even consider her. Also, Harry doesn't really know anything about Lily at all besides what he saw in the pensieve. We already know that that memory can be deceiving, since Lily and James ended up married even though they appeared to hate each other in it. Snape didn't necessarily hate Lily either. Calling her a 'Mudblood' might have been a ruse. He is a Slytherin, after all. (Just ask the Draco/Hermione shippers.) Well, you've probably figured out by now where I'm going with this. I believe Snape and Lily had some kind of friendship/relationship. Here are the reasons why (in addition to what I've already said, obviously):
1) Lily was good (better than Snape, according to Slughorn) at Potions.
2) Hermione says the HBP's handwriting looked like a girl's and Hermione is almost always right unless she's being emotional, which doesn't apply here.
3) Human nature. Lily stood up for Snape, and even though he still called her a mudblood, (he is a Slytherin, after all) I am told that most boys would have a crush on her from that point forward.
4) Why would Lily help Snape at all? I can't really see Hermione stepping in for Malfoy, can you?
5) Why was the memory Harry saw "Snape's worst memory"? It's bad, yes, but as James and Sirius' worst enemy, I hardly think it was an isolated incident. It is plausible, however, that it was the only one that Lily saw. Didn't Sirius and Lupin say something about Lily not knowing too much about how often James and Sirius cursed Snape? Hmmm...
Okay, so I'll summarize this a bit. Snape told Voldemort about the prophecy. Voldemort almost immediately began plans to murder the Potters (but not Lily, for unknown reasons, I'll get back to this.) Snape heard about the plans and immediately regretted telling Voldemort about the prophecy. Knowing that Dumbledore already knows about the prophecy, Snape goes to Dumbledore and pleads his case. He doesn't want Lily to be killed. Dumbledore, believing in the power of love, accepts his story. Snape becomes a spy for the Order of the Phoenix. Now that he has Dumbledore's trust, he applies for the Defense Against the Dark Arts job. Dumbledore knows that it's cursed so he offers him the recently vacated job of... Potions. *hem, hem* In my opinion the job was open because the teacher had just gone into hiding. But that's a story for another editorial.
That's pretty much what I've concluded so far. But why, I hear you asking, would Snape have tried to save Lily if he knew that Voldemort didn't want to kill her? My answer: He didn't know that Voldemort didn't want to kill her. This reason seems the more plausible of the two. Voldemort intended to do the murders himself, so there was no reason for him to tell his Death Eaters whom he was going to kill or not kill. I see it as going something like: Snape tells Voldemort about the prophecy and Voldemort tells Snape to begin trying to find out where the Potters are. I think his intention in finding the Potters is implied. He didn't have to cackle and say, "I'm going to kill the all," for Snape to guess what was going to happen. There is another theory out there that Voldemort was only willing to spare Lily because Snape asked him to. I find this mildly plausible at best. Voldemort did say, however, in Goblet (pg 649):
"Worthless and traitorous as you are, you helped me... and Lord Voldemort rewards his helpers...."
Snape DID help him, but I really don't think that he would have spared Lily, who had defied him three times, remember, just for Snape. But then he didn't think she was worth anything, so maybe her defiance didn't count. Anyways, I'm going to stick with the assumption that there was another reason that Voldemort would have spared Lily. (Probably something to do with her eyes that keep being mentioned.) And that Snape didn't know that Voldemort would *try* to save her.
Well, that's my take on the events surrounding the Potter's death. I've read so many editorials about whether Snape is a Death Eater now or not, that I thought I'd write one about why he changed sides in the first place. I hope you enjoyed it!
note: re-posted from my dead blogger