This documentary series sets out to investigate the history behind UFO sightings.

The first programme "The Innocent Years" takes a look at the sightings reported prior to the famous Roswell incident.

In "Cause for Alarm" the Washington DC UFO sightings of 1952 and the secret world of Area 51 are under investigation.

"Nightmare" sees alleged UFO abduction victims recounting their stories, while scientists and psychologists give their opinions about these claims.

"Aliens and Contact" follows the members of S.E.T.I (Search for Extraterrestrial Intelligence) man a huge radio telescope which searches the universe for life.

Genre: Documentary