But the diagram was already there. It's plastered across the wall in the background of the video, plain as day, a meticulous collage in green, easily two metres in diameter and showing the same meme complex to a hundred times the level of detail. There are smaller diagrams of different elevations arrayed around it like spores.

"How do you fight an enemy without ever discovering it exists?" the Wheeler in the video asks. "How do you win without even realising you're at war? What do we do?

The other Wheeler presents her finished diagram. She has drawn a mutated, fractally complex grasping hand with fivefold symmetry. It has no wrist or arm, just five long human fingers pointing in five directions. At its core, there's a pentagonal opening which could be a mouth.

"Marrion it's me."

The Marrion Wheeler in the video is seated, and looks unfamiliar in a way which takes the one watching a moment to put her finger on. Not exhausted, not sick, not physically injured; she's seen herself that way before, in the mirror. This woman's willpower is gone. She's beaten.

"Every competent antimemetics research project finds it's fingerprints sooner or later. It manifests all over the world, in thousands of different forms. Most of them aren't even anomalous. Some of them we already have catalogued separately in the main database. A very small number of them are even in containment. Impossibly virulent cults, broken arithmetic, invisible spiders as tall as skyscrapers, people born with extra organs which nobody can see. That's the raw data. Those manifestations are troublesome enough to deal with in their own right…"

"When that happens, when you make 'eye contact', it kills you. It kills you and it kills anybody who thinks like you. Physical distance doesn't matter, it's about mental proximity. Anybody with the same ideas, anybody in the same head space. It kills your collaborators, your whole research team. It kills your parents; it kills your children. You become absent humans, human-shaped shells surrounding holes in reality."

The Wheeler in the video casts around, picks up a bright green felt-tip pen and a blank piece of paper. She begins drawing a shape which isn't visible from the camera's perspective, while still talking.

She's still drawing. It's detailed. She doesn't look up, and her tone of voice is distant, almost as if she's narrating the tail end of a frightening children's story.

"Do you see it, Marion? See it now."

"But once you get a little further down the road you start to see a pattern emerging in the data. You need to have the training in memetic science, but once you have that training and you have the data in front of you, it only takes a little extra effort to arrange those data points in conceptual space and draw a contour through them. Those data points are points on SCP-3125's hull; those manifestations are the shadows it casts on our reality, and you see it… And it sees you…"