The NASA Files: The team analyses incredible NASA footage of reported UFOs, and interviews former NASA employees who allegedly witnessed cover ups first hand. (S1, ep 10)

The Silencers: UFOs are the biggest mystery of our time and somebody - or something - seems determined to keep it that way. (S3, ep 9)

UFO Storm: In 2008, the UK's Ministry of Defence released decades' worth of classified UFO files to the public. One month later, UFO hysteria ripped through the country. (S2, ep 9)

Vortexes: The team travels to Sedona, Arizona, long known for strange phenomena, to interview witnesses to unexplained sightings of lights and objects in the skies. (S1, ep 9)

Underwater Area 51: The team investigate the highly secretive underwater testing facility AUTEC, said to be used by the US Navy for weapons testing and underwater research. (S3, ep 8)

Alien Fallout: After seeing an odd flying object in 1980, a woman was hospitalised as she lost clumps of hair and skin. The team reopens her potential 'alien effects' case. (S2, ep 8)

UFO Dogfights: The team examines a declassified US Department of Defense report which analyses an alleged encounter between a fighter pilot and a UFO. (S1, ep 8)

Alien Harvest: The team investigate eyewitness reports of cattle slaughter allegedly caused by UFOs, and are hot on the trail of a recent mutilation case. (S3, ep 7)

Lost UFO Files: The team recovers physicist James McDonald's lost research, including interviews with more than 500 witnesses of UFOs and revealing government documents. (S2, ep 7)

Invasion Texas 2008: The UFO Hunters travel to Stephenville, Texas to investigate multiple reports of strange lights in the sky. (S1, ep 7)