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 joins UFO researcher Nick Pope and investigates a recent wave of UFO hysteria in the United Kingdom which started soon after the Ministry of Defense released formerly classified documents in May 2008.

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.

For years, the team has been tracking an elusive prey only seen at night--ships, shaped like triangles, impossibly huge, and videotaped over cities around the world. But are they ours, or theirs? The team investigates numerous UFO sightings that have recently been reported in Sonora, California, a charming old West town nestled in the Sierra Nevada Mountain Range nicknamed Triangle Alley. What makes these sightings so compelling are rare daytime footage of triangles in flight. This footage will be digitally analyzed to determine if these are indeed UFOs and not military jets. The team will also visit Texas to speak to military experts and witnesses to compelling triangle sightings. It's speculated that these triangle craft have been visiting us for centuries

The team looks into the claims of undercover investigators and former military personnel that an alien base exists somewhere below the New Mexico desert where human-alien hybrid experiments are being performed and how the beings there actually had a deadly conflict with human infiltrators.

The team studies two alleged alien abduction cases with alarmingly similar details that involve encounters with the creatures known as "Greys," and then they closely examine a strange humanoid skull found in Mexico that could be the remains of an alien-human hybrid.

The hunters delve into the mountain of reports from the Gulf Breeze, Florida UFO sighting wave of the early 1990s and then looks for possible connections to recent reports from Guantanamo Bay, Cuba of alleged Unidentified Submerged Objects (USOs) spotted rising from the ocean.

The team ventures to Germany and Poland to investigate rumors that the Third Reich had reverse engineered alien technology and may have produced a functional spacecraft, and how some of this technology was captured by the United States and helped jump start the U.S. space program.

The team investigates the phenomena of cattle mutilations, investigating a recent slaughter and following patterns of other cases, as well as sightings of black helicopters which have led some to believe the military may be involved in the killings as part of a secret experiment.

Investigating so-called "trace cases," the team studies supposed physical evidence left behind after various UFO sightings, from a strange glass-like rock found in Poland, to an odd piece of metal a Missouri man claims to have found after it was dropped from a UFO.

The investigators monitor the activity of the AUTEC (Atlantic Undersea Test and Evaluation Center), which is used by the U.S. Navy for underwater research, but the increasing reports of UFO and USO activity surrounding the facility have lead to rumors the base is testing alien technology.

The investigators analyze various UFO cases from around the world through the Freedom of Information Act, separating fact from fiction to determine what are obvious hoaxes and what could be legitimate evidence of UFO phenomena.

The team investigates the phenomena of orbs, (mysterious balls of light that appear to coincide with earthquakes), and travel to areas of orb activity in Arizona, Indiana and Missouri where some witnesses claim the spheres are intelligent and communicate through dreams and premonitions.

The team tries to gather insight on the military's "First Response" protocols, the alleged recovery and cover-up procedures that are followed in case of a UFO incident. The investigation takes them to a claim of a military pursuit of multiple UFOs near Long Beach, California and a return visit to the supposed UFO crash in Needles, California in 2008.

The hunters delve into cases involving witness interrogation by mysterious agents known as the "Men in Black" (MIBs), who sometimes appear suddenly after a UFO event, exhibit unusual behavior, know facts that have not been divulged by witnesses, and threaten the lives of those involved with severe consequences unless they remain silent about their encounter.