Snape & the Map (was The Worst of Severus Snape)

[virtualworldofhp]

No: HPFGUIDX 32686

--- In HPforGrownups at y..., "Allen, Rebecca" <Rebecca.Allen at t...> wrote:   
<snip>
> Snape probably imagines that Lupin gave Harry the map to lure him
out of school and into Sirius's clutches.

What I've never understood is how Snape suspects what Harry is holding
is the Map.  Well, granted he may not know exactly that the piece of
parchment was the Marauder's Map, but something about it obviously
drew his suspicions.  What was the "direct from the manufacturers"
comment?  Lupin always gave me the impression that absolutely *NO
ONE*, save the Marauders themselves, knows/knew about the Map, so why
does Snape have suspicions.  It's clearly something more than Snape
thinking, "Hmmm, Potter has old parchment in his pocket--clearly
something illegal and up to no good!"--that's just far too much of a
stretch for me.  What gives with Snape's actions?  A Flint?

-Megan (who knows Snape is unnaturally suspicious, but thinks JKR
paints it out to the fact that we obviously suspects something about
the Map and that this is inaccurate)