I had always thought that the idea of the Gunpowder Plot was to destroy the Houses of Parliament. I didn't realise that it was mainly to dispose of King James I/VI and his sons, and abduct his daughter and set her up as a puppet queen. Nor did I know about the Shakespeare link.
I found this very well researched and reasonably easy to read, if a little dry in places. The main bug for me, though, was the pronunciation of Coughton Court. Cuffton? Cowton? Corton? It wasn't until I had finished the book that I thought to do some Googling. Apparently the family that live there pronounce it Coton.