UFO Hunters

The team heads to Sonora, Calif., to explore whether sightings of triangular ships are indeed UFOs or attributable to military aircraft; the team builds a model of a triangular UFO based on an ancient artifact found in Colombia.

People recount their stories of encounters with grey aliens; an astrobiologist analyzes artist renditions of greys to try to determine what planets the creatures might inhabit; 900-year-old skull found in Mexico.

Satellite images show what appear to be underwater landing strips and other strange evidence in the wake of UFO sightings in Gulf Breeze, Fla., and reports from Cuba reveal unidentified submerged objects rising from the ocean.

The team analyzes the phenomenon of cows being slaughtered in the same strange and meticulous way around the world for the past four decades.

The team investigates videos indicating a strong UFO surveillance presence at weapons laboratories.

A growing phenomenon involves purported sightings of UFOs known as orbs, whose witnesses report experiencing odd dreams, premonitions and deep fear; the team investigates orb sightings in Arizona, Indiana and Missouri.

The team tries to uncover U.S. military forces' first responses to UFO encounters; investigating a claim that military helicopters pursued UFOs over Long Beach, Calif.; revisiting a suspected UFO crash site in Needles, Calif.

Reports relate instances of men in black, bent on silencing UFO researchers and witnesses to alien encounters; analyzing the only known photo of the men in black; a Utah site is rumored to be the base for a legend.