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)
Inside UFOs: Those who claim to have been abducted by extraterrestrials give their accounts of the interior of their spacecrafts. (S4, 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)
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)
The Freedom of Information Act: In 1969, the US government officially announced it would stop investigating UFOs, but declassified documents seem to tell another story. (S4, ep 3)
The 1952 Wave: In Spring 1952, reports of UFO sightings shot through the roof. Can former US Air Officials shed any light on this? (S4, ep 2)
Second Skin: To enter space, humans require a space suit. Are the aliens that are said to have visited earth any different? Or are they more akin to artificial drones? (S4, ep 1)
First Contact: As humanity continues to search for alien life, experts give their analysis on how close we are to First Contact. (S4, ep 20)
Artificial Alien Intelligence: Is biological life merely a stepping stone for a universe dominated by alien artificial intelligence? (S4, ep 19)
Alien Communications: With light from distant stars taking millions of years to reach us, how long might it take for alien life to answer any communication sent into space? (S4, ep 18)