"Oh, hadn't you noticed? An unfortunate side effect of some research. I've replaced most of it."
"The cupboard over the sink," Minerva tells him (said cupboard is still quite well-stocked from two Christmases ago). "Do help yourself. I'll move the books." She goes to gather her research materials from the kitchen table in case the gentlemen do in fact decide that they are eating here. She has the distinct feeling she wasn't supposed to show up. This, of course, makes it much more necessary that she do so.