https://en.wikipedia.org/wiki/Jack_Parsons_(rocket_engineer)

After a brief involvement with Marxism in 1939, Parsons converted to Thelema, the English occultist Aleister Crowley's new religious movement. In 1941, with his first wife Helen Northrup, Parsons joined the Agape Lodge, the Californian branch of the Thelemite Ordo Templi Orientis (O.T.O.). At Crowley's bidding, he replaced Wilfred Talbot Smith as its leader in 1942 and ran the Lodge from his mansion on Orange Grove Avenue.

Helen went away for a period in June 1941, during which Parsons, encouraged to do so by the sexually permissive attitude of the O.T.O., began a sexual relationship with her 17-year-old sister, Sara. In 1945 Parsons separated from Helen; when Sara left him for L. Ron Hubbard, he conducted the Babalon Working, a series of rituals designed to invoke the Thelemic goddess Babalon to Earth. He and Hubbard continued the procedure with Marjorie Cameron, whom Parsons married in 1946. After Hubbard and Sara defrauded him of his life savings, Parsons resigned from the O.T.O. and held various jobs while acting as a consultant for Israel's rocket program.

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The Babalon Working was a series of magic ceremonies or rituals performed from January to March 1946 by author, pioneer rocket-fuel scientist, and occultist Jack Parsons and Scientology founder L. Ron Hubbard. This ritual was essentially designed to manifest an individual incarnation of the archetypal divine feminine called Babalon. The project was based on the ideas of Aleister Crowley, and his description of a similar project in his 1917 novel Moonchild.

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https://www.onlyinyourstate.com/southern-california/devils-gate-ca/

Beginning with the first people who inhabited Pasadena’s Arroyo Seco, there have been rumors of a spiritual connection to the place. The Tongva believed water running through the gorge sounded like laughter, which they attributed to the coyote spirit.

In the 1920s, the narrowest place in the Arroyo Seco was dammed to control flooding, and it was named Devil's Gate Dam, for the demon-like face of a horned figure in the natural rock outcropping.

In the 1940s, a group of occultists became interested in the area and attempted rituals intended to open a portal to Hell.

The group included rocket scientist Jack Parsons (a follower of Aleister Crowley's Thelema) and L. Ron Hubbard (future founder of Scientology). Their goal was to bring forth a "moonchild," which they hoped would be an Antichrist figure that would lead a Thelemic revolution.

In the 1950s, after Parsons perished in an accidental explosion, several children went missing in the area around Devil's Gate Dam. Though none of them were ever found, a serial killer took credit for two of the disappearances 13 years after they went missing. As the man, Mack Ray Edwards, was a construction worker at the time, their bodies were hidden somewhere in the concrete of California's freeways.

Two other children seemed to have vanished into thin air, one after turning a corner in front of his parents, and the other while returning to a YMCA campsite. In both instances, the children only left supervision for a matter of seconds when they somehow disappeared

This reminds me of all those "missing 411" stories about people, especially children, vanishing in national parks after being unsupervised for only a few seconds. There are quite a few stories of children vanishing into thin air immediately after "rounding a corner" in a national park.

Later, during the so-called "Red Scare", Parsons, Unable to pursue his scientific career, without his wife and devoid of friendship, decided to return to occultism and embarked on sexually based magical operations with prostitutes. He was intent, informally following the ritualistic practice of Thelemite organization the A∴A∴, on performing "the Crossing of the Abyss", attaining union with the universal consciousness, or "All" as understood in Thelemic mysticism, and becoming the "Master of the Temple". Following his apparent success in doing so, Parsons recounted having an out-of-body experience invoked by Babalon, who astrally transported him to the biblical City of Chorazin, an experience he referred to as a "Black Pilgrimage". Accompanying Parsons' "Oath of the Abyss" was his own "Oath of the AntiChrist", which was witnessed by Wilfred Talbot Smith. In this oath, Parsons professed to embody an entity named Belarion Armillus Al Dajjal, the Antichrist "who am come to fulfill the law of the Beast 666 [Aleister Crowley]".