From microscopic particles, to large pieces of unknown metal--UFO "trace cases" offer some of the most convincing evidence that UFOs may have been visiting earth for centuries. Our team examines the most compelling relics available. In Pennsylvania, they uncover reports of a UFO spraying a strange blue mist, witnessed by multiple people. They examine a mysterious glass-like rock found in Poland at the scene of a UFO sighting. And in Missouri they meet a man with a unique otherworldly piece of metal he witnessed falling off a UFO. Our team will conduct a scientific test never-before-done on this unidentified metal. The results of this test could be revealing.