Picture it: It's March 14, 1919. New Orleans. You pick up your copy of your local paper, the Times-Picayune, and read an extremely interesting letter:

Hell, March 13, 1919 Esteemed Mortal of New Orleans: They have never caught me and they never will. They have never seen me, for I am invisible, even as the ether that surrounds your earth. I am not a human being, but a spirit and a demon from the hottest hell. I am what you Orleanians and your foolish police call the Axeman. When I see fit, I shall come and claim other victims. I alone know whom they shall be. I shall leave no clue except my bloody axe, besmeared with blood and brains of he whom I have sent below to keep me company. If you wish you may tell the police to be careful not to rile me. Of course, I am a reasonable spirit. I take no offense at the way they have conducted their investigations in the past. In fact, they have been so utterly stupid as to not only amuse me, but His Satanic Majesty, Francis Josef, etc. But tell them to beware. Let them not try to discover what I am, for it were better that they were never born than to incur the wrath of the Axeman. I don't think there is any need of such a warning, for I feel sure the police will always dodge me, as they have in the past. They are wise and know how to keep away from all harm. Undoubtedly, you Orleanians think of me as a most horrible murderer, which I am, but I could be much worse if I wanted to. If I wished, I could pay a visit to your city every night. At will I could slay thousands of your best citizens (and the worst), for I am in close relationship with the Angel of Death. Now, to be exact, at 12:15 (earthly time) on next Tuesday night, I am going to pass over New Orleans. In my infinite mercy, I am going to make a little proposition to you people. Here it is: I am very fond of jazz music, and I swear by all the devils in the nether regions that every person shall be spared in whose home a jazz band is in full swing at the time I have just mentioned. If everyone has a jazz band going, well, then, so much the better for you people. One thing is certain and that is that some of your people who do not jazz it out on that specific Tuesday night (if there be any) will get the axe. Well, as I am cold and crave the warmth of my native Tartarus, and it is about time I leave your earthly home, I will cease my discourse. Hoping that thou wilt publish this, that it may go well with thee, I have been, am and will be the worst spirit that ever existed either in fact or realm of fancy. --The Axeman

What the heck, right? Would you even dare to NOT go to a jazz club that night?

And then nearly 100 years later, the letter in question pops up on one of the biggest subreddits, r/todayilearned:

Who was the Axeman? Is this true or an urban legend?

The answers are a little fuzzy. But here's what we know: There was a serial killer in 1918-1919 in New Orleans, dubbed "The Axeman" by the Times-Picayune. And the scene at the jazz clubs the following Tuesday night, March 18, 1919, was, as the kids today say, lit. Nobody was attacked that night.

And the Axeman was never caught.

Dirk Gibson, a professor of communication and journalism at the University of New Mexico, specializes in serial murders. (Also product recalls and outer space studies... because, why not?).

He says as many as a dozen people were attacked in New Orleans with axes, from 1918-1919. Most of them were Italian grocers, attacked with their own axes.

The Times-Picayune, played up these murders to the salacious hilt, says Gibson. The stories were often speculative and fantastical, tapping into fears of the supernatural and the occult.

It spooked the city.

In some ways, it seems like the Axeman's letter could have only worked in New Orleans. Post-Civil War, the city's demographics completely changed, says Bruce Raeburn, curator emeritus of the Hogan Jazz Archive at Tulane University.

The large plantations had been broken up after the North's victory and thousands of African-Americans poured into the city, living with whites, Creoles, Jewish people and more. And the new music of the time and the place — jazz — reflected the multicultural experience.

"It was a young people's music, and many of the neighborhoods that produced jazz musicians were what demographers would call a crazy quilt," says Raeburn.

"To some extent, jazz was heading in the opposite direction of segregation, which was trying to separate people," he says. "For young people in New Orleans in 1918, 1919, they really gravitated to jazz and the blues."

And, it seems, so did the Axeman.