That does sound disappointing - I've enjoyed several of Walters' mysteries, especially The Sculptress, but I'll remember to give this one a miss.

I am most boggled by the cat part. The clergy did not shun cats! Sometimes they cursed them for doing annoying cat things - like anyone else enslaved to a feline - but they did not shun them. I mean, never mind the pawprints, there's this other famous monkish remark on a page otherwise left blank:

Here is nothing missing, but a cat urinated on this during a certain night. Cursed be the pesty cat that urinated over this book during the night in Deventer and because of it many others too. And beware well not to leave open books at night where cats can come.

... which just goes to show that cats have not changed very much in the intervening centuries. Since Medieval books were at serious risk of being eaten by rats and mice, though, I'd say the monks ultimately came out ahead no matter how often they knocked over the ink or used the vellum as a litterbox.