This short video is known only by the title 11B-X-1371, and in the short months since it appeared online, no one has been able to solve its mystery. Some think it’s an elaborate puzzle, while others think it’s a warning of some kind.

The only thing we know is that it’s scary as all hell.

Note: You can watch the full video at the end of the post. If you dare.

The video first appeared online in May when it was uploaded to YouTube. It appears to be shot in an abandoned building surrounded by thick woods.

It features a lone figure which moves about the room while executing unexplained hand motions – while a deep buzzing sound blares in the background.

Sequences of characters, codes, and symbols flash on screen at different times, but their meaning is unclear.

Word of the video got out after a copy was mailed to a writer at a popular tech website in Sweden. The writer didn’t know what to make of it, so he asked the Internet for help. And what people found is really freaky.

At first, the video may seem like a prank, but there’s a complicated mystery behind 11B-X-1371, and it has people everywhere utterly captivated. The first mystery was the video’s title, a binary sequence that translated to “Te queda 1 año menos,” or in English, “you have one year less.”

 But it gets even more disturbing. Someone ran the audio file from the video through a spectogram, a machine that can create a visual representation of any noise. This is what they saw:

Buried in the audio representation were images of what appeared to be a person being brutally tortured.

The image was accompanied by words that read, “Your are already dead.”

They also analyzed the codes that flashed across the screen. The first turned out to be coordinates for the White House.

A second frame turned out to have Morse code. It translated to “REDLIPSLIKETENTH.” When rearranged, the letters read, “KILLTHEPRESIDENT.”

A third text appears at 1:51 in the video. It’s a cipher text that translates to, “SOON COMES THE FALL / ANOTHER GREAT EMPIRE. THE FALL / THE EAGLE ON THE HORIZON. JOIN US. THE EAGLE = INFECTED WILL SPREADD HIS DISEEASE. WE AARE TTHE ANTIVIRUS WILL PROTECT THE WORLD BODY.”

The flashing light on the figure’s hand is also in Morse code. It reads “2015THEREWILLBE(THREE).”

Some people think that the video might be a warning from a serial killer, or maybe even a confession of past crimes. Theories about some kind of religious cult have also been floated, citing the mysterious figure’s clergy-like robes.

The theme of viruses also comes up a lot. In addition to the mention of viruses in the decoded text, the figure is dressed in a plague mask.

These masks, which originated in the 17th century, were worn by men called plague doctors.

The masks themselves were stuffed with an assortment of spices and herbs, including vinegar and camphor. This was meant to keep away bad smells from sick patients, as well as the disease itself.

One minor breakthrough was made when Internet sleuths found the room where the video was filmed. It was part of the old abandoned Zofiówka Sanatorium in Otwock, Poland.

Watch the full video on the next page.

If you dare.

Some believe that this is a masterful prank. Others think it’s meant to be a warning, perhaps of a future catastrophe of some kind. All we know is that it’s scary as anything we’ve ever seen. What do you think?