I listened to the great Hugh Fraser read the novel and had to wrack my brain to keep up with the story. The TV show is even worse in this regard. It barges past the viewer (past me anyway) with breakneck speed. I note, however, on IMDb that ten whole minutes were subtracted from the original British version for the easily-distracted American audience, which is used to ADHD-inducing commercial interruptions that shorten TV shows of all sorts. In other words, the producers (or editors) of the British version realized that millions of Americans wouldn't sit still to absorb the full show in its original length. I suppose that the shortening of the show accounts for some of my confusion and for my feeling that important points in the plot ended up on the cutting-room floor.
Other than the incomprehensible plot, the show is magnificent, drenched in period atmosphere and in fabulous acting from everyone in the show.
Back to my complaint: I imagine that if the crew had done Hamlet, the show would have stopped at "To be. That is the." How tragic that intelligent American viewers able to sit still for a longish television show have been cheated by whoever cut a large hole in this otherwise wonderful production.