This docuseries returns for its sophomore edition bearing more firsthand eyewitness accounts in the premiere "UFOs in Combat," wherein the show's all-star team embarks on a new series of investigations, aided by a fresh collection of military testimony. At the heart of the episode are multiple accounts of encounters between U.S. military personnel and UFOs, dating back to the days of the Vietnam War. Some of these reports seem to suggest the possibility that such unidentified aircraft have been shadowing American pilots for decades.