Eureka! Snape and the Marauder's Map

[pippin_999]

No: HPFGUIDX 34626


I believe I have solved the mystery of Snape's behavior when he 
interrogates Harry about the Marauder's Map in PoA. That is, if 
Snape knew something about "the manufacturers", why didn't he 
question Lupin more directly?

<theory>
I am kicking myself, because I should have realized this as soon 
as I finished GoF. The name Snape recognizes from the Map is 
*Wormtail*. He doesn't know it from Hogwarts, he knows it from 
being a Death Eater, and (this is the kicker) he thinks "Wormtail" 
is Voldemort's code name for the traitor  *Sirius Black*.  It doesn't 
matter that there's no physical resemblance between Pettigrew 
and Black, even in Death Eater robes. A little polyjuice goes 
along way, as Snape knows perfectly well. 

When Snape summons Lupin to his office, Lupin has no idea 
that Snape knows anything about Wormtail, and of course *he*  
thinks Wormtail is the one person who *couldn't* have given 
Harry the Map. Thus the stage is set for a comedy of errors. 
When Lupin says, "Wormtail or one of those people?" it's the 
perfect wrong remark. Snape is bound to believe that Lupin is 
baiting him (again!) but he can't question Lupin more directly 
without revealing the source of his knowledge. 

This  explains why Snape doesn't repeat his threat to destroy the 
Map: it's evidence. It makes Snape's continued complaints to 
Dumbledore about Lupin perfectly understandable, and it also 
makes sense of Snape's outright refusal to listen in the 
Shrieking Shack. 


Snape sees the activated Map in Lupin's office, the map which 
proudly bears the name of someone Snape knows to be  Death 
Eater.  It's obvious to Snape that Lupin is in league with Black, 
either as ally or dupe. He runs out to the Shack, and discovers 
that Sirius has hostages. Then the kids start telling him some 
wild story about Pettigrew. Snape is in no mood to listen, and 
there's no time. Lupin could turn into a bloodthirsty monster at 
any moment and he hasn't had his potion. *Of course* Snape 
ties  Lupin up.  It's quite sensible of him.

But Snape doesn't behave like a reasonable man, and this, I 
believe, is why. Suppose Snape is the spy who revealed to 
Dumbledore that someone close to the Potters was giving 
information to Voldemort. Snape told Dumbledore he suspected 
this person, known only as Wormtail, was in reality Sirius Black.  
Snape has believed all these years that James chose to 
disregard this warning and trust Sirius anyway. His berating 
Harry for arrogance in the office gives some basis for this. Then 
he's told that James actually did switch Secret Keepers, and 
picked Pettigrew who really was the traitor. So it's  all Snape's 
fault. Snape can no more admit to guilt than Lupin admit to 
anger. Snape goes into hysterical denial and no wonder.

He thinks  Black might at any moment reveal that  Snape himself 
is a Death Eater, something Harry would be quite willing to 
believe.  Snape also  dares not give Black a chance to bewitch 
him.  Wand or no wand, Black is dangerous. He managed to get 
out of Azkaban without a wand, who knows what he can do?  So 
Snape announces that he intends to turn Black over to the 
Dementors, which is what even Harry thinks the traitor deserves, 
and gets blasted unconscious for his pains. 


Then,  thanks to Lupin, Pettigrew gets away, leaving the whole 
issue still in doubt. Really, looking at it this way, Lupin got off 
easy. If I were Snape, I wouldn't have bothered spilling the 
secret,  I'd have murdered him outright. <g>

</theory>

 Fire away!

Pippin