Mostly because of Dune. See, there's this bit... the Baron has people who have a nifty heart valve installed - a little plug in their chest that can be pulled out and poof, the blood drains out of their heart, out through the hole in their chest, death and all.

I have yet to find a way to put words to it properly, but I've been daydreaming for several days now about something similar. Little insets on the wrists of house slaves, locked (through magic or technology, take your pick) in such a way that only the Owner can open them, but she can do so with the quickest of touches. Imagine what it would be like, going through your life with those little valves set into your body, knowing that you could be drained dry, left empty and dead, at the slightest whim of the one who Owns you... instead of hanging your head, or kneeling to the whip, or any more common gesture of submission, when you had offended or displeased you would kneel with your wrists offered upward, bared and waiting. Occasionally there would be pools of blood to clean up, and you'd know that one of the slaves had failed to be pleasing, had been disposed of. Imagine the feel of the little valves as you press your wrists against your hips in almost a protective movement. Imagine feeling your Owner's hands clasping your wrists, fingers brushing over the valves, teasing, taunting... leaving you so very aware of how easily you could be killed.

I imagine an entire House where all the slaves are fitted with such valves - not just wrists, but one at the throat as well. In fact, most would have only the one at the throat; a collar would be a very physical sign of protection, as it would cover up the valve, make it impossible to get to without removing the collar. The sheer terror in a slave's eyes when they had been displeasing enough to be denied a collar... so delicious an image. The ones who, even if collared, also had their wrists implanted, they would be constantly aware that they were unlikely to survive for long. Somehow they had been chosen, marked, given a rather fatal role... and it wasn't a question of IF they would die at their Owner's hands, blood spilling out onto the floor, rather it was a question of WHEN.

I wonder what their reaction would be to something as simple as a kiss on the wrist?