The Endless (2017)

This mind-bending thriller follows two brothers who 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.