Watch Project Blue Book, Tuesdays at 10/9c! It could be one of the darkest and most sinister secrets in the entire field of UFO investigation: human-alien genetic experiments, reportedly going on deep below the New Mexico desert brush in an underground base. Learn more in Season 3, Episode 2, "Underground Alien Bases". #UFOHunters Subscribe for more from UFO Hunters and other great HISTORY shows: po.st/SubscribeToHistory Find out more about this and other specials on our site: po.st/History_UFOHunters Check out exclusive HISTORY content: History Newsletter: po.st/HistoryNewsletter Website - po.st/HistoryWeb Facebook - po.st/HistoryFacebook Twitter - po.st/HistoryTwitter HISTORY®, now reaching more than 98 million homes, is the leading destination for award-winning original series and specials that connect viewers with history in an informative, immersive, and entertaining manner across all platforms. The network's all-original programming slate features a roster of hit series, epic miniseries, and scripted event programming. Visit us at www.HISTORY.com for more info.