After a containment breach/wild encounter with the anomalous, multiple civilians and foundation staff are killed. The only survivor, a foundation researcher, soon finds that some of the corpses are not humans. They are humanoid aliens, with multiple devices that allow them to blend in with humans.
The researcher goes on to discover that many of these aliens are hiding in plain sight, blending in with humans in the "normal" world, and some posing as foundation staff. The researcher hides the SCP article from everyone else in the foundation, since he doesn't know who's really human.
Eventually, he determines that the only people he can trust are D-class, since they die so much he doubts that the aliens would have any agents there. Through a series of interview logs, the researcher makes a team of D-class that help him figure out what the aliens goals are, so the researcher can find a way to contain them. There's a few exploration logs of the D-class testing for who's with the aliens, with some coming back with positive results.
Then the researcher will confront one of the aliens, trying to capture them. The alien escapes, and the article will end with a message from the site director ordering the immediate termination of the researcher.
Finally, there will be a link to a tale from the aliens point of view that will show their true intentions.
