In qntm’s #ThereIsNoAntimemeticsDivision, the Unknown Organisation secures, contains, and protects* all manner of strange entities (‘Unknowns’). The #antimeme‎s are by far the strangest: information-based ‘self-keeping secrets;’ photo-negative ideas that survive by preventing their own repetition; though they may be extensively documented by UO, they are persistently forgotten when not being observed. Every time a member of the Antimemetics Division works with an antimeme is the first time. Over and over. Mnestics (psychoactive drugs only available to UO employees) help maintain awareness of antimemes while at work, but they don’t last.

Antimemes are far, far weirder than I suggest. Can they be eerie? Early on in the story, one character encounters an enormous Unknown that overshadows the UO Wyleigh building; they’ve never seen it before. U-9429 is a 91x91x147m black basalt monolith, with smooth, uniform rectangular extrusions across its surface (12.5x5cm), as well as entrances and stairwells. It looks human-made, but that’s impossible: the basalt doesn’t come from the area, and it weighs some 3 million tonnes, making it so massive that moving it in one piece would defy the laws of physics. UO holds a wealth of knowledge of many alien/eldritch entities – it wasn’t built by aliens, either.

After a page or two of speculation, one of the characters gives the answer: It’s an antimemetic structure, so it was created by an antimemetic culture. You’d think that’d ruin the eerieness, but the main conceit of antimemes is that they are the ultimate ‘something’ where there should be nothing. There might be an antimeme in your room as you’re reading this, right now, and you will never know, because we are physically and mentally incapable of experiencing whatever stimulus their non-existence puts into the world. Some antimemes will isolate you, feed on your memories, and than erase the memory of you from everyone else’s minds. It may look like someone at your work, who just barely doesn’t fit in – but by the time you notice this, it’s already too late.

There is much the Organisation doesn’t know about U-9429, and the entities who built it. For all anyone knows, they could still be out there. To quote Fisher, again:

> The problem here is not why the people who created these structures disappeared – there is no mystery here – but the nature of what disappeared. What kinds of being created these structures? How were they similar to us, and how were they different? What kind of symbolic order did these beings belong to, and what role did the monuments they constructed play in it?