An explosive congressional hearing reignites a decades-long fight for government transparency on UFOs. A whistleblower provides explosive testimony. Fighter pilots and military personnel describe strange sightings, and the U.S. government is forced to consider a new approach to how they analyze and make public UFO sightings.

A former Navy pilot, who helped blow the whistle on the government's secrecy around UFOs, becomes an advocate for commercial pilots who have nowhere to report the sightings their trained eyes cannot explain. Activists push for legislation to address the toll, the issue takes on pilots.

Scientists across academia take matters into their own hands, employing a variety of cutting-edge tools to study UFO phenomena. Using AI, precise radar systems, advances in physics and analyses of historical images, they hope to collect data that reveals the source of these mysterious sightings.

For as long as there have been sightings of strange objects in the sky, there have been reports from those who say they've encountered entities associated with the phenomena. Despite the stigma attached to speaking out, people share stories of their extraordinary interactions.

A revealing look at what happens when the phenomenon gets deeply personal. Beyond sightings in the sky, people relive encounters they describe as abductions. Renowned Harvard psychiatrist John Mack, comes under attack for taking them seriously.

No longer waiting for the government to reveal everything they know about UFOs, citizen scientists and privately funded organizations are making advances in data collection. In the air and under the seas, exploration continues to push for answers to the ultimate question: Are we alone?