Residents of a Texas town report strange lights in the night sky and claim to have seen US Air Force planes in hot pursuit of UFOs. Did they witness an alien visitation? From the depths of the ocean, scientists record one of the loudest sounds in the natural world. Can they determine its mysterious source? And, a fishing trawler vanishes in perfectly calm waters off the Northern California coast only to be found mysteriously undamaged on the ocean floor. What happened?