Out of turn order, but since knowledge checks and talking are instant...
Lucy remembered reading about something like this. It had interested her enough to conjure up apparent copies of the creatures and see how the servants reacted to them; they had reacted with complete terror, and she'd only been able to keep them in place by reminding them of the debts they owed her family. She could see why now.
They're shadows. Undead things, like ghosts but worse. For the Saint's sake, don't let them touch you.