At night they come to collect the debt. The loans that we took, for the things that we bought. Like an itchy blanket they swarm the city, each seeking out their target. If you sleep, you won’t notice. Stay awake and you’ll hear them buzzing, feel them pricking, mining you for the resource they desire.
Currency was too roundabout anyway, too inefficient. Why sell your soul when you can just sell part of your vessel? It freaks people out though, even just seeing it happen. No way they’ll do it to themselves just so they can buy a meal. It’ll ruin their appetite! So at night, tiny drones come to withdraw the blood payments you own. Apparently it’s useful for research, or whatever they do with it. Just, try to be asleep for it.