My Whole Life Depends on a Barber's Whim

A quick thought for today: I was at the barber shop today. While he cut my hair off, I couldn't stop thinking about one thing: "My whole life depends right now on the barber's whim." As anyone of you who has watched Sweeney Todd (or read about him) knows, a barber can decide to finish the life of his customers without the customers' ability to stop him (or her). 

This led me think about roles in our RPG stories that are also like that, making the customer depend on their whim. What follows is a list of such roles, and an idea about how they can be used to encompass this idea. The why, you see, is pretty simple: a) Because we can do it, as GMs. b) It can be interesting and dramatic. c) It will make the PCs mortal, and as such will make the game richer and more challenging. So, anyway, on to the list:

• Barber: Nothing much to say, except for, you know, going for a Todd's style.
• Chef: Have you thought once about the possibility that when coming to a restaurant, they may be poisoning the food? It won't be hard to do it. The kitchen is normally far, most of the ingredients aren't recognisable anyway, and most of all, because the kitchen is open to see, no one will suspect what's happening there.
• Potion seller/brewer: Nothing too fancy or surprising. Who wouldn't buy an anti-poison potion? Make this anti-poison a real potent poison and you've got a hit. After all, it only gives a bonus...
• Judge: What if one of our beloved murder hobos is gonna be hanged?
• Ship Captain: Remember the scene from Pirates of the Caribbean, where Jack almost throws Will to the water? How about the lone island scene?

So, how about you? Do you have something similar in your games?