A few things on the miniseries
I did read the book, and I know Christopher's mother was mentioned as another girl in the house, but the show gave me the impression that Sugar was Christopher's mother. Did anyone else think her behavior implied that?
Also, just a casting opinion: Both actresses were great, but I think the casting of Mrs. Fox (Shirley Henderson) and Lady Bridgelow (Elizabeth Berrington) should have been reversed. Neither fit their own description from the book, but they fit the other's. It did annoy me that Mrs. Fox was portrayed as Dr. Curlew's sister rather than his daughter.
The wild, cruel animal is not behind the bars of a cage. He is in front of it.