1989: a mysterious SOS sign beckons from the Japanese wilderness. The mystery of who built it, however, remains unsolved to this day.
Aboard a Japanese passenger flight, a structural component fails - leaving the 524 passengers on it to plunge through the night sky.
Nexpo, also known as Nightmare Expo, is a YouTube channel that specializes in analytical video essays exploring internet mysteries, eerie websites, and gaming-related urban legends. His most well-known series is Disturbing Things From Around The Internet, but he also produces content such as Internet Investigations, Gaming Retrospectives, Console Conspiracies, and Three Minutes or Less, along with various other horror-themed videos.