"Out of the darkness, two voices spake unto me"

[desperance]

There I was, just walking: and two guys came by me, yabbering away in some language that I don't speak; which is not unusual at all in this neighbourhood, but the thing is, they were both speaking at once. Not across each other, not interrupting, not arguing: just both talking, hammer and nails, barely a pause for breath, at the same time as giving every impression of listening to the other. It was ... impressive. And apparently commonplace to them.

So then, of course, I started thinking. Could there be a language that actually required that, that needed two minds, two simultaneous inputs actually to mean anything? Like the two sides of a zip-fastener, meaningless until they interlock...

And then of course I wondered how you'd think. And where the story was, because of course there has to be a story.