A triangular-shaped aircraft seen over Tinley Park, Illinois is investigated. Similar reportings were made around the same time all around the world.

Police officials in Ohio, Michigan and Illinois talk about the cases of UFO they have examined in their areas.

The hunters head to Kokomo, IN. to check out a report of a high decibel boom which was felt and heard for miles and caused a flood of emergency phone calls. Included are theories of what may have caused such a loud noise.

The 1897 crash of a alleged UFO in Aurora, Texas in examined. Also, a search for the grave of the aircraft's alien pilot was believed to be buried.

A retrospective which examines the July 1947 in the New Mexico Desert of Roswell, where an alien ship purportedly crashed. Included are new theories, among them is a second crash may have occurred.

An investigation of the formation of lights seen above the Phoenix skies in 1997 and 2008.

n the early 1950's, James McDonald, a senior physicist at the University of Arizona, changed the entire course of UFO research. For nearly 20 years he examined UFO reports in great detail – interviewing over 500 witnesses, uncovering important government documents, and testifying before Congress in 1968. He challenged skeptics, performed scientific analysis, and led the charge for UFOs to be properly studied. After his tragic death in 1971, his investigations and files were sent to the University archives, where they lay dormant...until now. The team brings these lost UFO files back into the public eye for the first time on television, and looks at evidence long thought lost to history.

The investigators take a look at close encounters of the second kind, such as the December 29, 1980 case of Betty Cash, and Vickie and Cody Landrum, who claimed they encountered a fiery object hovering over a road that emitted intense heat and allegedly left them suffering symptoms of radiation exposure.

The team probes the skies over England following an airline pilot's official report of a pair of UFOs he believed to be at least a mile in length, and a review of other sightings of gigantic unidentified craft seen over the United States.

The hunters investigate the growing number of encounters between commercial aircraft and UFOs, highlighting a November 2006 incident at O'Hare International Airport in Chicago and a 2004 sighting in Osaka, Japan.

The hunters try to find what the military covered up in a recent May 2008 crash of an unknown object in Needles, California, and looks at other famous crash incidents like the Kecksburg, Pennsylvania case where the military supposedly undertook a massive clean up effort and intimidated local witnesses.

The team finds new vantage points to spy on the recent activity at Area 51, which in the past decade has acquired more public lands to increase perimeter security, and built new towers, buildings and runways for the continued development of top secret aircraft.