This island in the middle of San Francisco Bay has a forbidding reputation. Native Americans believed it to be a place of evil spirits. When it became a federal prison in 1934, only the most violent and difficult prisoners in the U.S. were sent there. It was reputed to be escape proof; only three men have ever managed to get off the island. They left in 1962 and have never been found. MysteryQuest investigates to determine whether they could have survived the icy waters of San Francisco Bay.

To this day no one knows the true purpose of Stonehenge, the ancient monument in the British countryside. There are many theories: a shrine celebrating a god; an ancient solar calendar; or maybe a sacrificial altar for an unknown pagan religion. MysteryQuest travels to the ancient ruin with a new theory–that ancient people may have used the sound reverberations inside this circle to induce a trance-like state among participants in ancient rituals. Were there bizarre rituals, even sacrifices, to some long-forgotten god? The team will attempt to find evidence that could crack open this persistent mystery.