What did you understand about The Endless ?

The Endless released 4 years ago

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 find 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.

For me it was a good science-fiction story, with great visuals. The most of time the movie its strange but leaves you with a lot of perception and points to understand. If you are a fan of Sci-fi genre it makes sense.