I had stumbled across your stories from time to time over the last few years, but recently I started back from the beginning and binge read the series.
I'm now in withdrawals, sweating and shaking badly - only another chapter will cure me. Please hurry Dr. Southrook :-).
I love the way you combine a good mystery / action adventure story with some amazingly inventive bondage devices and predicaments. That's a combination that is rare in BDSM writing and you have mastered it. Your character development is also quite good - I feel as if I know these people.
I am a little surprised the guards don't 'take advantage' more often, they seem almost inhuman in their ability to stay professional.
You may have the entire story arch already in your head, but if you're looking for some ideas - I love a good public crucifixion. Victim should be tied to the cross (not nailed of course) with a slanted foot support that puts her knees at 45 degrees. Then the focus is on "the dance" as she alternates between hanging from her wrists and not being able to breathe and pushing up with her legs (which she can't quite lock) until her leg muscles quiver.
Other devious ideas include:
The Chinese water torture (drops of water slowly dripping on the forehead, hitting the same spot again and again). Insex did this years ago and the model got such a headache from it after just a few minutes that they had to stop the live shoot! This sounds like something Brandy would HATE.
More forced exercise or work - I LOVED the Armstrong device. I also love the idea of women having to do completely useless but agonizingly hard work, like moving 40-50 lb stones from one pile to another pile across a large room or field, just to have to move them back again. Perhaps the women are attached to an overhead cable and there is a large truck scale under each pile that knows when they have moved a rock and punishes them if they don't keep up the pace. Many industrial loading docks have such scales under where the trucks back into the dock. Perhaps The Kingdom has a set of loading docks that could be used for this?
Anyway - keep up the good work and keep writing, there are people out here waiting for your most excellent writing!