When two experts build their own radio-listening station to intercept the secret communications of American and Soviet astronauts, they capture traces of a haunting voice that may be a lost Russian cosmonaut.

When a powerful radio beam originating from deep space is detected by experts on earth, some suspect it's hard evidence of extraterrestrial life; new investigations into this shocking signal might reveal the truth.

A Russian radio station has broadcast a signal nonstop since the Cold War, and no one knows why; experts use hi-tech methods to investigate what it is, and what might happen if it ever stops.

When someone picks up a radio distress call from a seven-year-old boy lost alone in the desert, authorities embark on a search-and-rescue mission to find him; as the hunt continues, the case becomes more and more mysterious.

When a US Air Force intercept aircraft chases after a UFO, it vanishes forever without a trace; a new investigation tries to uncover what caused this mysterious disappearance.

At the tomb of one 3,000-year-old Egyptian pharaoh, experts report that the massive statues that guard the site can sing; using cutting-edge technology, investigators hunt for an explanation for this mysterious phenomenon.