A ghost appears on the Gettysburg battlefield, a sea monster surfaces in Ireland, and UFOs are spotted over Philadelphia and The Hague.
Unwelcome Visitors: If aliens have visited Earth, what are their intentions? Do they wish to experiment on the human body, or the human mind as well? (S4, ep 8)
The Next Wave: A fascinating look at the mounting evidence that suggests UFO waves are able to penetrate the world's most closely guarded airspace at will. (S2, ep 8)
Inside UFOs: Those who claim to have been abducted by extraterrestrials give their accounts of the interior of their spacecrafts. (S4, ep 7)
Alien Skies: From mid-air abductions to near-disasters caused by unseen enemies, experts examine if we are alone in the skies over Earth. (S2, ep 7)
Seeing is Believing: For decades, governments around the world have investigated UFO sightings. How are these top-secret studies conducted? (S4, ep 6)
Top Ten Military Encounters: A fascinating and shocking countdown of the top ten military encounters between Earth's armed forces and UFOs. (S2, ep 6)
The Shoot Down Order: Jets are scrambled to intercept a UFO, but find they are unable to complete their Shoot Down Order. (S4, ep 5)
Alien Apocalypse: If extraterrestrials visited Earth would they enlighten us or destroy us? Experts examine the possibility of a doomsday orchestrated by an alien enemy. (S2, ep 5)
Atmospheric Anomalies: Some experts believe many atmospheric light shows are actually caused by extraterrestrials. If so, do they pose an imminent threat to humanity? (S2, ep 4)