To start with I enjoy historical whodunnits. I find they put flesh on dry old characters I learned about at school. Cassandra Clark is up with the best and her Abbess of Meaux is a believable and enthralling character, usually.
Clarks research seems from reading the past three novels to be on the button without distracting from the readability of the novel.
Having said this I now find myself feeling somewhat of a pedant. I am interested in falconry. Hawks, falcons and falconry are an integral part of the plot line in the latest mystery and yet Clark seems here to have done no research whatsoever. We hear that a hawk has killed a small deer at one point. No it has not. Hawks are too small and lightweight to kill even the smallest of deer. They may feed from deer carrion but will not actively hunt any of the native species of deer which are all much too large. Rabbit and hare being about the largest prey animals even a female Buzzard or possibly Goshawk (being larger than the male) will go for. (None of the falcons will)
We further hear that a hawk or falcon has taken a man's eyes out because he had some meat tied to his face. I suppose this is just about possible if not feasible. Raptors are trained initially to eat only from the falconer. They were in the days of this book manned by feeding them from the fist. The falcon,(I presume because the falconer was so upset when he had to pull it from the victims face and kill it) in question would have been an expensive Peregrine, Saker or Lanner. All birds suitable for a prelate such as the Archbishop of York (the rules for who could own what being very strict. He could not own a Gyrfalcon for instance or any of the eagles) would perhaps have fed on the carrion tied to the mans face, if nothing else was available. It is highly unlikely that these birds would not have been kept in peak condition and only kept hungry if they were about to hunt.
I would not be so pedantic about tihese incidents in such an elaborate and usually quite acceptable storyline if they had not been essential to the plot and consequently so jarring when read. Poor or no research in such a story really is inexcusable. This really has let the book down for me.