What exactly did Snape do in OOTP?

[Steve]

No: HPFGUIDX 129251

--- In HPforGrownups at yahoogroups.com, "niekycrins" <n.crins at p...> wrote:
> We know that Snape became spy for DD before LV fell. DD even gives
> evidence in Snape's trial. I assume therefore that LV knows that Snape
> was a spy for DD, and that he refers to Snape as "the one who has left
> him forever, and who has to die". So, if LV knows, how could Snape
> spy? Also, since LV calls his DE by their names, they know of each
other.
> So what did Snape do? Could he be spying on LM, maybe LM doesn't know
> of  Snape being a spy? Or maybe Snape is double-crossing, but I doubt
> whether DD would fall for that
> 
> Nieky

bboyminn:

Well, there is much and in mean MUCH speculation on this, but the only
thing I've been able to come up with is that Snape is a double agent.
Each side thinks Snape is spying for them.

If Voldemort originally sent Snape to Dumbledore as a spy against the
good side, but then Snape, unknown to Voldemort, became a spy for the
good side, then we can explain everything that appears to be happening.

Snape appears to be working for the good side, but at the same time,
even by his own statements, Snape appears to be in contact with the
Death Eaters and most likely even with Voldemort. So, how can both be
true? Again, the only logical explanation I can find is that each side
thinks Snape is a spy against the other.

If each side thinks Snape is a spy, then they can make allowances for
apparant loyalty to the opposite side. In other words, there are time
when in order for Snape to be a good spy for Voldie, he must do things
that make him appear loyal to Dumbledore. If Dumbledore suspects Snape
isn't loyal, then he won't trust Snape, and he then becomes an
ineffective spy for Voldie. 

Just as he must at times appear loyal to Dumbledore and appear to
betray Voldie, there will logically come a time when he must do the
opposite, appear to betray Dumbledore and appear loyal to Voldemort.
Such is the nature of a double agent.

Lots of people have other ideas, but I've yet to find another one that
explains how Snape can still be in contact with Death Eaters. Snape
himself said to Harry that it was Snape's job to spy on Voldemort. The
only way to appear loyal to Voldemort is if he is appearing to spy on
Dumbledore. 

This whole double agent/triple agent thing gets complicated and
convoluted when you try to explain it, but I think you probably still
get the main point.

Just one man's opinion.

Steve/bboyminn