More On Snape's Backstory

[cindysphynx]

No: HPFGUIDX 34690

Tabouli has already cracked the mystery of why Snape hates 
Harry. ::waves to Tabouli who is working diligently to keep the Good 
Ship L.O.L.L.I.P.O.P.S. off of the rocks::  

One of the biggest remaining mysteries about Snape is why he decided 
to work for Voldemort, and equally important, why he decided to come 
back to Dumbledore.  Did Snape really, deep down, believe in the 
things the DEs believe (purity of blood, etc.)?  Did he just want to 
be on the winning team and wrongly predict that Volemort would win?  
What on earth was Snape thinking?

OK, here's a theory (using as much canon as I can), and it all turns 
on The Prank.

Snape is a Hogwarts Slytherin, and he shows up knowing a lot of 
advanced curses.  Snape isn't very popular with the student body at 
large due to his greasy hair and tendency to glide and prowl.  But 
Snape gets on well within Slytherin and with his head of house, 
Karkaroff, who has, uh, taken an interest in young Severus.  Snape's 
buddies are all Slytherins who eventually turn out to be DEs.  Snape, 
however, isn't so sure he wants to go that route, and he is still 
deciding what his future holds, despite Karkaroff's attempts to win 
Snape over by providing, uh, wine.

Meanwhile, the Marauders are making Snape's life miserable.  They 
bewitch parchment to insult Snape.  They torment him about his greasy 
hair.  They snicker about how his talents are in potions, which is 
for wimps, as they pull off flashy Transfiguration tricks.  Sirius is 
handsome and popular, while James is the revered Quiddich Jock.  The 
two of them get away with all manner of rule-breaking, right under 
Snape's hooked nose.  Lupin is good at DADA and loyal to his new 
friends, so he can defend against any curse or hex Snape might think 
of trying.  Peter doesn't have much going for him, but he sneaks 
around spying on Snape, telling James and Sirius the best way to 
torment Snape.  Snape doesn't complain to Dumbledore, of course, but 
stews silently, prowling around hoping to catch the Marauders doing 
something worthy of expulsion, coping the best he can.

Then Sirius plays The Prank, almost getting Snape killed, and scaring 
the pants off of Snape.  Snape goes to Dumbledore, figuring he 
finally has the goods on 3 of the 4 Marauders.  Sirius should be 
expelled for The Prank and the rule-breaking that led to it.  James 
clearly knew about it, and should be expelled.  Lupin was in on it 
too, Snape figures, and Lupin should be expelled on general principle 
because werewolves have no place at Hogwarts.  

Snape tells this to Dumbledore, demanding an apology and hoping for 
expulsion.  Dumbledore, however, wants to protect Lupin and doesn't 
want everyone knowing that Dumbledore admitted a werewolf to Hogwarts 
and cooked up this ineffective Whomping Willow protection.  So what 
happens?  Snape gets no apology.  Maybe there's a detention for 
Sirius and a few points from Gryffindor.  That's it.  To add insult 
to injury, *Snape* is sworn to secrecy about Lupin's werewolf 
condition.  The Marauders are free to smirk at Snape and disrespect 
him as though nothing happened, and Snape can't do a thing about 
it.  ::shrugs off mental image of Sirius howling like a werewolf 
everytime Snape passes in the halls::

This is just too much for Snape to take.  Dumbledore has shown who he 
favors and where his loyalties lie -- the Gryffindors and the 
Marauders.  This solidifies Snape's relationships with the DE 
Slytherins and slams the door on any possibility that Snape will join 
Dumbledore's team.  Figuratively speaking, Snape finally accepts 
Karkaroff's wine.  :-)  Upon graduation, Snape really has nowhere 
else to go other than join up with the DEs.  He certainly isn't going 
to join up with Dumbledore, and he trusts the judgment of his fellow 
Slytherins, like, uh, the Lestranges, Travers, Mulciber, Karkaroff, 
Rookwood, Crouch Jr.  Snape figures joining the DEs will give him the 
two things he would never get from Dumbledore:  power and respect.

Once Snape becomes a DE, he finds it is not all it was cracked up to 
be.  It isn't the purity of blood issue or the muggle-torturing that 
bothers him.  Snape is sufficiently mean-spirited to tolerate these 
things.  Instead, Snape discovers that Voldemort really is the Prince 
of Lies.  Although Voldemort and the DEs promised Snape power and 
prestige, Snape is just a journeyman DE, outside the outer outskirts 
of Voldemort's inner circle, hardly in a position of power.  Snape 
figures that there is nothing to be done about this, so he resolves 
to just live with it and keep his head down.

Eventually, Snape is given an important DE task to perform:  get some 
intelligence on the Potters.  Although Snape would dearly love to get 
even with James, he has divided loyalty because of his affection for 
Lily.  Also, Snape really has no way to accomplish this task because 
he was never really close to James.  Snape doesn't come up with 
anything.  Voldemort, believing that Snape isn't trying hard enough 
and needs some motivation, punishes Snape with several protracted 
Cruciatus Curses and a substantial tongue-lashing.

And that is the moment when Snape decides to defect back to 
Dumbledore's camp.  He sees that he will never amount to anything as 
a DE, and unlike Wormtail, he has enough pride to be unwilling to 
tolerate constant verbal and physical abuse.  At this point, however, 
Snape only has one thing anyone would want:  the trust of the DEs and 
Voldemort.  And the only person who would want what Snape has is 
Dumbledore.  So Snape goes back to Dumbledore, admits his error, begs 
forgiveness and agrees to spy on Voldemort.

Before Dumbledore will take Snape back, however, Snape has to prove 
his loyalty.  Dumbledore wasn't born yesterday, there is a war on, 
and there is steel under his fatherly exterior. Dumbledore isn't 
going to trust Snape until Snape does something that puts Snape at 
personal risk and proves Snape's loyalty to Dumbledore, something a 
Voldemort spy would never do.  Dumbledore tells Snape that Snape must 
do more than just name the names of DEs.  He must help apprehend 
these DEs.  Dumbledore proposes that Snape must arrange an ambush of 
as many DEs as possible.  The only DEs that Snape can really deliver 
to Dumbledore are Snape's old gang of Slytherins.  

Snape agrees.  What choice does Snape have, really?  If he somehow 
gets Dumbledore to accept him back, Snape won't be safe anywhere but 
Hogwarts with his old DE friends and Voldemort all hunting for him.  
So Snape lures his old friends (Travers, Mulciber, Dolohoff, Rosier, 
Crouch Jr., the Lestranges) to a trap in which a certain talented 
Auror (Moody) kills some and takes the rest into custody.  Moody 
becomes famous for his exploits in this ambush, making his taunts of 
Snape in GoF all the more mean-spirited.  

Snape continues spying after this ambush, telling Voldemort and the 
DEs that he only just escaped the ambush, and finding his own 
position in Voldemort's camp greatly enhanced now that Voldemort has 
lost some members of his inner circle.  Unfortunately, Snape's 
promotion occurs too late for Snape to learn that Wormtail is a DE 
prepared to betray the Potters.  

As for Sirius, Snape despises him and always will.  Not because 
Sirius wouldn't apologize for The Prank.  Not because Sirius wasn't 
nice during their Hogwarts days.  Not because Snape is jealous.  No, 
Snape despises Sirius because The Prank was the catalyst for Snape's 
decision to become a DE and all of the pain Snape suffered as a 
result.

Well, it's a theory, anyway.  
  
Cindy