Earth Portals: Experts unravel the secrets of the universe's earth portals: shortcuts through space that allow travellers to span vast distances in the blink of an eye. (S2, ep 13)

UFOs from Earth: For years many have argued that UFOs are as terrestrial as you or I. They may be correct, but not in the way they thought they were. (S4, ep 12)

Triangle Terror: For years, the flying saucer has been synonymous with UFO terror. But is it still the spacecraft that frightens us the most? Or has fear taken a new shape? (S2, ep 12)

UFO Photos: As the world continues to evolve into the digital age, more and more people are capturing images in the sky that they are unable to explain. (S4, ep 11)

UFO Metal: Nations all over the world are rumoured to have found metal debris from UFO crashes. Join the investigation into the alleged wreckages of otherworldly crafts. (S2, ep 11)

Finding Aliens: Advances in technology have given us unprecedented access to distant galaxies that may harbour life. However, alien life may be found closer to home. (S4, ep 10)

Antigravity: Experts discuss the possibility of advanced alien technology that could allow UFOs to fly at blinding speed or hover effortlessly a few feet above the ground. (S2, ep 10)

Alien Journeys: Alien encounters have offered a possible glimpse into the secrets of interstellar navigation. Could this one day ensure mankind's survival? (S4, ep 9)

Signs of Abduction: From loss of time and bizarre hazy memories, to terrifying accounts of alien surgery, these are the hidden signs of alien abduction. (S2, ep 9)

Fast Eddie: While the guys pick the back roads of Minnesota, they challenge Danielle to sell a 10-foot fiberglass cowboy boot that's been gathering dust for more than a year. (S4, ep 11)