So, most of the threads aren't finished yet, but
our alien friends? They've been possessed by
the demons from the book. And now they're
lurking in the cornfield and occasionally invading the barracks. Anyone who is outdoors at night (even inside the barracks walls) may be attacked by them. Anyone who goes into the cornfield at any time of day will be attacked by them.
They can be injured, but they can't be killed until they've fulfilled their mission - which happens to be killing the person who set them free. Sorry, Aisling. However, the person who summoned them is also capable of trapping them in the book once more, she just has to read the spell inside it. Too bad Aisling can't actually read... But if anyone wants to go into research mode, the book is still in the library, and it will tell you about the demons' need to kill the person who summoned them and how to banish them and everything.
On the bright side, the Wood has taken it upon itself to protect you somewhat from the unkillable demon-aliens: anyone killed by the demons will "respawn" in the cornfield... where they will be continually hunted by the demons, and unable to leave the cornfield until someone still "living" finds them and leads them out, but at least they won't die permanently. So... enjoy your demons, Woodfolken!
Any questions you might have about the cornfield demons can be asked here.