THEM is a group of humans connected with empricon. THEM stands for (*Insert here*). They were able to put souls of old dragons into breand new dragons, creating a sort of in-between dragon. These dragons were like the necromancer's revived dragons, but much more reliable and much more powerfull.
After their encounter with Laura, Gal, Hope, etc. they vanished and nothign else has been heared of them.