This is based on a web series that is based on a random post from 4chan ages ago. The web series has something like 100MM views and was made by a kid starting when he was 14. That same kid, now 19, is directing this movie for A24. Pretty wild. The web series is a lot of found footage as well as footage from scientists and a company exploring the backrooms. Lots of lore around it and it's a pretty cool story but mostly appeals to the younger generation I believe. The movie is supposed to tie in to that but also be completely standalone.