I really liked the secret passages in these books. I think it was the first book that used them so much or effectively. JVJ second series uses them to though they are not as dominate in the story. Today I found out why she uses secret passages in her books so well and so often. She wrote all this below in her blog:

"It was only a matter of time before I started reminiscing. Here is part of the cellar Paul, Mark and I used to rummage around in as kids. I found this photo on the internet. I have no idea who the dude in the tuxedo is, but that’s absolutely, one hundred percent our cellar. Mum and Dad used to run a pub in England and, wonder of wonders, the local historical society has posted some photos of it online. I look at the photo and remember the rough-hewn walls, low ceilings, nooks and crannies, sealed doors and secret passageways and I can’t help but think, “Tomb of the Dhoone Princes.” Yes, the cellar had a real life secret passageway that was sealed after WW2. It was an evacuation tunnel leading from the church to the pub--or the other way around depending on the day of the week. This tunnel ran across the road, under the graveyard and into the church vault. In our day the entrance had been sealed with cement, but you could still see its shape and location. I haven’t consciously thought about it in years--decades even--but it’s been there, in my mind, asserting itself gently as I write."