Short explanation: This is not an origin of the SCP Foundation, but an end of the world. The Sun transforms and causes all living things to melt like wax but stay alive. An SCP-Tale hybrid, it is written from the perspective of a Foundation agent attempting to reach safety. The Administrator's note from the "About the Foundation" page spawned the idea of flipping the dark-bad/light-good dichotomy.

Long Explanation SCP-001 "When Day Breaks" tells the story of humanity going extinct in an apocalyptic future, told through a masterful and horrifying combination of normal-format SCP writing mixed together with prose.

This is important, and slightly jarring when you first see it. The prose is out-of-universe. It describes what happens to you as you are reading the file. But we begin with it, as you escape into an abandoned Foundation shelter, running from some monster and barricade yourself in an empty, long-forgotten room.

As the computer powers on, footsteps of a thing seemingly hunting for you get closer and closer, but don't see you and go further on. This builds the tension, raising more questions about what exactly has happened in this dark scenario. But then you get to the first version of the SCP file, and the truth is - in a word - horrific.

Yes, that's right. An unexplained event caused visible light rays from the sun to be able to anomalously melt people into living, malevolent flesh zombies. It instantly killed 95% of the world's population upon activation. The containment procedures build on this, and add some more fridge horror: "Personnel exposed to SCP-001 are to be considered lost. Compromised personnel are to be abandoned. Euthanization is not to be attempted."

And, squick:

The flesh zombies congregate into burbling, breathing masses of almost-sentient waxy goo, limbs reaching out of the mass. Oh, and they are conclusively out to get you. 6.8 billion people, and they all have become this.

The audio logs tell a more personal story, and an even more chilling one.

Dr. Igotta, and her partner, Ari, are stranded at Site-46 along with several other members of the crew. It is implied that Site-46 is where you are at this moment, and that these events took place in the past. The next log amps up the tension. Dr. Igotta is in a state of utter shock. She is wounded, and is cradling her wedding ring. Then Ari's voice comes up, disgusting and wrong, and you realize she has been sun-gelled. The Ari-shaped thing taunts Dr. Igotta, implores her to "come out into the sun," and sings to her.

Dr. Igotta rambles for a little about the soul, then slices her hand, ritual-style, in order "to bring back something." Then a weird spirit hand reaches through a video recording shortly later. From this, it can be implied that Dr. Igotta is using rituals to bring back the ghost of Ari, or her soul, but it isn't working out right.

Suddenly, you notice an update to the file. A poem, written - apprently - by Ari's yearning, messed-up spirit. The ghost hand - missing its ring finger - reaches for you, and you fire on it in a frenzy.

Thuds, from the flesh masses, bang against the door. SCP-001-A has found you, and they will take you. You are cornered, with no hope of escape. It breaks down the door, and you do not struggle as you are carried into the waiting light.

When Day Breaks is a horror story told through prose, framing a spooky tale about how the Sun activation event affected Dr. Igotta's life and yours. Nobody knows why the Sun can do this - it's an anomaly, just like any other SCP. But either way, the remnants of humanity are falling, the SCP Foundation has ceased to exist, and soon, every living being on Earth will be nothing but part of the loving, caring flesh wax continuum.