The Shrieking Shack-did Snape have ulterior motives?

[KathyK]

No: HPFGUIDX 85702

Laura:

>The night of the Shrieking Shack incident in PoA, Snape, as we 
know, appears in the Shack.  He tells the group that he found out 
what was happening when he went into Remus's office to give him his 
monthly wolfsbane potion and saw the Marauder's Map.  (PoA p.358 
US). As soon as he grasps the situation, he goes tearing off to the 
Shack.   But wait a minute-what about the potion?  Why didn't Snape 
bring it with him?  He knew that Remus would be a lethal threat to 
HRH if he didn't take the stuff ASAP.< 
 
KathyK:

But Snape didn't know HRH were there until he arrived at the 
Shrieking Shack, or at least until he found Harry's invisibility 
cloak.  He says he saw Lupin running off down the passage to the 
Shack and then disappearing.  The Trio and Sirius were already off 
the map.  He only knew Lupin was up to something and suspected it 
had to do with Sirius.  

Snape was in the room, though, throughout Lupin's explanation of 
MWPP's experience at school with Lupin being a werewolf and the 
others becoming animagi.  And who knows how much he heard before 
sneaking into the room?  So he was able to piece a lot of things 
together while Lupin spoke.  

So he didn't have any reason to worry about protecting the Trio 
becuase he didn't know they were there at first.  

Laura:

>If, on the other hand, Remus had already transformed, what did he 
think he could do against a werewolf and a murderer?  Why didn't he 
get some backup?
 
>I can only infer that Snape was so eager to nail Sirius and Remus 
that he didn't really care if HRH were killed in the process.  
Doesn't say much for our boy Sevvie, does it?  And then he has the 
nerve to paint himself as HRH's selfless rescuer.  Nice, Snape, 
really nice.<

KathyK:

He could still paint himself as the rescuer because once he was 
conscious, he *did* deliver Black to Fudge, thus protecting everyone 
from a convicted murderer.  

About the wolfsbane thing...Lupin didn't transform until they'd left 
the Shrieking Shack.  There are different theories as to why this 
was so.  But whatever the reason, maybe Snape knew Lupin wasn't 
going to be in werewolf form yet and thought he had ample time to 
take care of Lupin and Black.  He didn't anticipate HRH being there 
and Lupin's long drawn out explanations.  He didn't anticipate the 
Trio knocking him out, either.

Or maybe he was hoping Lupin would have already transformed.  Then 
he could kill Lupin and it would be self defense.  
  
>Laura, wondering who Snape would have gone after first if he had 
>been in the MoM that night-Sirius or Bellatrix?<

KathyK, thinking that is a very interesting question