[OOC: This went up yesterday - sorry. I was a bit confused as to the posting of the letters themselves. And yes, A. Edward is Edward Avery. He just isn't ready to bugger things up with certain DoM employees quite yet.]
The Order picks up that something is amiss on Diagon Alley, and when Death Eaters do show up (as they had dropped the clues in the tip line to intentionally draw the Order out) it launches the Alley into a battleground. Death Eaters turn on the Order to keep them busy, while continuing to make a stir with structural damages to shops not bearing signs against Muggle-born employment and patronage. Before long, the Dark Lord arrives, and a Patronus message is sent from the Order to Dumbledore, begging him to come. Only later does it become apparent about how the Death Eaters were not attacking anyone but the Order, and later on any D. M. L. E. who arrived.
The Complete Spell List is available here.