The passage is from the very end of the book.

They were also unaware that on the steep face of the higher mountain where the snow was a white curtain blotting everything from view, the wolves had gathered in a mass of darkness. It was a company of companies, a flock of flocks, and they had a great deal to communicate. It would be the stuff of wolf legend.

Not all of them had emerged unscathed from their mission. Between the pads of a paw, here and there, was a tiny sliver of red, blue or golden-yellow glass that had fallen from one of the bright pictures in the chapel windows. These pieces would need to be extracted, by tongue and teeth, because left where they were, they could make a wolf lame, and a lame wolf was slow and liable to succumb in the winter.

With thanks to InspiredImages (via Pixabay) for the photo.
Excerpt 2 from The Wolves of Little Mouse Valley