Randy Anderson, who served eight years in the Army Special Forces, was conducting weapons training at the Naval Support Activity Crane in Indiana when he and another Green Beret were escorted into an elevator and taken below ground.

'We moved down a hallway and entered an area with a marking on the wall that said 'Off-world technology,'' Anderson recalled. 'Immediately, alarm bells went off in my head. That's when the strange sh** started happening.'

Anderson described a room containing a 'metallic, basketball-sized sphere' that was 'levitating above a podium' and appeared 'unnatural.'