The Endless
Oh my god, it's a genuinely good indie movie.
This slow-to-start but original and ultimately entertaining mindfuck is a slow-burn, low-key gem in the same way as (and bearing some superficial similarities to, in terms of setting and tone, and how gradually and realistically it brings on the total weirdness) Yellowbrickroad, another rare zero-budget favorite of mine.
The Rotten Tomatoes summary probably summarizes it better than I could: "Two brothers receive a cryptic video message inspiring them to revisit the UFO death cult they escaped a decade earlier. Hoping to find the closure that they couldn't as young men, they're forced to reconsider the cult's beliefs when confronted with unexplainable phenomena surrounding the camp. As the members prepare for the coming of a mysterious event, the brothers race to unravel the seemingly impossible truth before their lives become permanently entangled with the cult."
That is about the…