Let's step away from mind games for a while. Exploring personal guilt and anxiety can be exhausting... as well as lethal. Your appetite for the Foundation's secrets hasn't diminished all this time, so... why don't we follow that line? I mean the simplicity of instincts. Eating and reproducing. Some of the... residents here only dedicate themselves to that, and it makes them a bit predictable to be honest, but there will always be a legitimate interest in their methods, no matter how cruel and inhuman they may seem...
Let's see... ah, 307. Truly fascinating once you know the details. It's surprising that it managed to go unnoticed for so long without causing major incidents. You know, dogs, cats... some curious child. It doesn't attract much attention either, everyone mistakes it with a common ivy that has a certain purple touch. One of the Foundation's agents discovered it in full action when it was devouring a nest of blackbirds. Almost by accident, I'd dare say. A later analysis revealed that its presence extends to the entire continent. Sometimes I wonder how we're still alive...
Obviously, the Foundation burns it to ashes every time it finds it in the wild, but it keeps a 'small' sample. It has its own pot, dedicated light, and automatic sprinkler. A whole personal hydroponic hotel... except it's enclosed in a stainless steel prison, no windows, with circular blades controlled from outside. No one can enter there... especially after the incident.
SCP-307 doesn't seem to be interested in insects, but whenever a warm-blooded animal approaches, several vines begin to grow in its direction until they touch it. Paralysis is immediate, and then it starts to wrap around it, almost like a spider preserving its prey. The consumption of its victim happens after it has converted every internal organ and every muscle into liquid. The only thing it leaves behind is the skin and the bones. All cavities are covered with a root system that begins in the skull of the victim. The Foundation performed some autopsies, and always found a seed there.
Now, I figure you must wonder why the Foundation needs to burn it. Well... SCP-307 has demonstrated a formidable resistance to the most popular poisons, and to rival plants. In one of the experiments, they placed a jar full of aphids to feed on the ivy. The aphids fell dead in less than five minutes. Some genius here thinks that reaction could be used as an insecticide. I say he's crazy...
Why? Because the last Class D who died manipulating SCP-307 helped us prove that the ivy is not stupid. Somehow it managed to find a small hole under one of the plates in his suit. That's no coincidence. SCP-307 possesses a certain intelligence, at least enough to circumvent our protection systems.
For now, containment works. But it wouldn't be pleasant if it managed to escape beyond the perimeter. The Foundation has drastic resources at its disposal to purge installations, and believe me, you don't want to be there when that happens...