It all started with a panicked phone call. A local landlady who owned a downtown tenement
building had called the police in hysterics. Something horrifying had happened to one of
her tenants; she couldn’t possibly explain. The one detail she was able to articulate
was that his room “looked like a rainforest.” A police response team was on the case in no
time. They drove down to the tenement building, met the crying landlady at the door, and found
their way to the room that’d caused all this confusion. When they opened the door, they
saw with horror that she was right - trees, plants, fungi, and even insects and animals were
all over the room. It was teeming with life. The flora and fauna in this room didn’t
look like anything else on Earth. And given the anomalous nature
of what had happened here, it’s extremely possible they were right. The
tenant - a university professor who’d recently gone on an anthropological expedition to the
Amazon rainforest - was nowhere to be seen. But one of the officers spotted a grim
clue for what may have happened to him. A large colony of anomalous mold
was quickly growing on the far wall. The officer swore it was
a trick of the mind at first, but he was wrong. A human skull was sinking into
the tissue of the mold, and to make matters worse, whipping tendrils began to slither from the
empty eye sockets reaching for the new meat. Thankfully, for everyone who was still alive at
this point, the SCP Foundation swooped in and took over the situation with the help of a Mobile
Task Force and some containment specialists. The landlady, the cops, and the other residents of
the building were given amnestics and relocated. The building was purchased by the Foundation and
condemned while they searched the anomalous room for the source of this unchecked biological
growth. And they found their answer in a most unlikely form: An unmarked cassette tape,
still inside the player when they arrived. The recording on this cassette tape came to
be known as SCP-407. It may seem unassuming when compared to immortal, misanthropic
lizard-monsters and multi-dimensional chaos gods, but the tape in that room, if it fell into
the wrong hands, could cause a mass ecological catastrophe that would inevitably bloom into
a dreaded XK-Class End of the World Scenario. So, first thing’s first: What’s actually on this
tape? Thanks to brief samples heard in tests with D-Class Personnel, The Foundation was able to
discover that it was an approximately 28 minute long recording of a song. It’s performed
in an unknown language, and appears to be sung acapella style by a group of unknown
individuals. Fearing potential degradation of the cassette tape, the Foundation backed it up
as an audio file in the Site 19 Computer Database. Those who’ve been able to listen to the song
during testing have had an overwhelmingly positive emotional response - describing it
as 'soothing', 'glorious', and 'beautiful'. And for the first minute of its runtime, the
song’s anomalous effects really live up to this reputation. When the song is played, it massively
accelerates cell growth within its auditory range. Its potency is increased by the volume
and the length it’s allowed to play. It’s important to note that plugging
or covering your ears won’t make any difference. The area of effect seems to be
defined by how far the sound vibrations travel, and whether you’re actually
able to hear it is irrelevant. But if you’re only listening for a minute or less,
you’ll be glad to feel the anomalous effects of being within SCP-407’s auditory range. During
this specific period of time, it’s been shown to be a kind of miracle-cure to almost all physical
maladies, with the exception of cancer. Thanks to the cell growing and rejuvenating properties of
the song, the Foundation discovered that 407 was an effective treatment for Alzheimer's disease,
Crohn's disease, brain and spinal cord injuries, and normally fatal infections or wounds,
amongst other maladies. It was like a version of SCP-500 - the pills that cure
everything - but one that would never run out. So, if it’s such an effective healer, why wasn’t
it more widely employed by the Foundation? Because of what happens if you keep listening. If the song was played for two to three
minutes, the subject would begin to experience unnecessary and unchecked cell
growth - particularly on the skin. The result would mostly be benign tumors and calcium and
fat deposits, which though sometimes painful and disfiguring, are not life threatening. At
minute four, single celled organisms in the auditory vicinity of the song begin to experience
accelerated mitosis, also known as cell division. This results in bacterial and fungal
growth that becomes extremely dangerous for anyone and anything exposed. And beyond
minute five, things become truly monstrous. The Foundation only ever conducted two
tests wherein the song was fully played. These tests presented such a huge danger
that further testing of 407 was forbidden without explicit permission
from a member of O5 Command. The first test involved a female member of D-Class
Personnel in a soundproofed but unsterilized testing chamber. As expected, she was initially
delighted by the music. It cured her injured knee and brought her back to a state of peak physical
fitness. But this didn’t last for long. She soon began to report intense dizziness and stomach
pain, resulting in severe sickness. At this point, anomalous plant growth began in the corners of
the testing chamber. It seemed as though a whole ecosystem was coming to life and evolving
at an impossible fast rate in the chamber. Over the next few minutes, the D-Class
experienced a nightmarish physical transformation. Her skin became a thick, callused mass.
She soon devolved further into a thick, immobile blob of pure flesh, unrecognizable
as anything human while the chamber around her was becoming a lush rainforest of alien plants.
These plants grew around and eventually on her until there was nothing left. Shortly
after, all the plants died and decomposed, giving away to a huge mound of anomalous
mold devouring the resulting mulch. The mold itself began to evolve, growing large
mouth and hand-like structures that it used to feed itself on the surrounding flora and fauna
as it began to grow back. When the song ended, the Foundation brought the test to
a close, sterilized the room and collected some samples for later. There was
nothing left of the original D-Class subject. The second test wasn’t any nicer. While at first,
the subject - this time a male member of D-Class personnel - appeared to become more youthful
and even gain an inch of height, as the minutes passed, he began to experience extreme discomfort.
He soon began to vomit - with the vomit quickly blooming into plants. Plant shoots also began
to quickly spring out of his eyes and mouth, until his entire body was destroyed by what
appeared to be a banana tree suddenly growing out of it. Once again, the testing chamber became
a whole ecosystem - this one filled with unique, never before seen mammals. However, it all
came to an end when the room was taken over by a fast-growing, parasitic fungus that consumed
everything else with its spores and fungal stalks. And it looked like it was breathing. There was something concerning about both of
these tests - beyond the obvious physical horror of watching death-by-unchecked-cell-growth. What
was this mysterious fungus that kept appearing, and seemed to take over everything it
touched in the end? The Foundation tested the samples it collected rigorously,
and came to a surprising conclusion: They’d actually encountered this same
fungus before, but not in this dimension. SCP-507 is a man with dimension-hopping abilities.
The one problem is, he can’t control where and when he hops. As a result, he’s been stuck
in a number of scary alternate dimensions, but one seemed eerily similar to what the
Foundation was encountering with SCP-407. In one dimension he briefly hopped into, 507 encountered
an abandoned version of Site 19, strewn with corpses covered in that same breathing mold. He
was horrified, but decided to inspect further, hoping to find his way out of the facility and
discover some answers about what happened here. However, when he found his way out, what he
discovered didn’t comfort him. The entire world seemed to be covered by this same mold. There
was nothing left. It’d consumed everything. Thanks to Foundation tests, both
molds were found to be similar to the Cordyceps Fungi - a kind of dangerous,
parasitic mold. Except this one appeared to be a far more evolved and even
more deadly version of the fungus. What could this mean? What was the origin
of this anomalous song? Would it and the fungus it seems to inspire someday destroy
the world as we know it, and kill us all? We’ll never actually know the answer to any of
this, and it’s thanks to an extremely unlikely ally: A Person of Interest nicknamed L.S.,
a prominent member of The Serpent’s Hand. This enigmatic figure had previously come into
possession of SCP-268 - a hat that made them almost impossible to detect. With the help of this
hat, L.S. breached Site 19 in an incident that was later dubbed Security Breach Incident X23.
While it’s believed that L.S. mainly broke into the facility to make use of SCP-914, they performed a curious action along the
way: They hacked into the Foundation database, and deleted all traces of SCP-407,
effectively neutralizing it. In a note left by L.S., they said “You’ll
thank me for deleting what you call ‘407’.” Why would a member of The Serpent’s Hand,
a Group of Interest that is often militant in their anti-neutralization stance,
neutralize an SCP themselves? The answer to this lays in who exactly L.S.
Is. This mysterious figure isn’t technically one person - they’re a group of the same
person, namely a woman named Alison Chao, from a number of different dimensions.
They meet in the Wanderer’s Library, the headquarters of The Serpent’s Hand that exists
between dimensions, to coordinate their missions. Why does this matter in regards to SCP-407?
Because the nature of L.S. allows them to know what’s going on in a huge number
of dimensions at once. This means, much like the brief glimpse given by SCP-507,
L.S. likely knows about another universe where 407 and its horrific mold has already caused an
XK - Class Scenario and destroyed the world. And if it happened there due to poor
biological containment measures or 407 falling into the wrong hands, it could happen
here too. Unless, of course, someone stepped in and dealt with the problem personally. And while
the Foundation’s policy is typically to contain rather than neutralize the anomalies they
find, we have to admit, we’re probably with the Serpent’s Hand on this one. Some songs, as
it turns out, are just better left unplayed... Now go watch “SCP - 073 & 076 - Cain Vs Able”
and “SCP - 5031 - Yet Another Murder Monster” to absorb even more knowledge about the
beings contained by the SCP Foundation.
