Although it's not as famous as the Bermuda Triangle, the Alaska Triangle has more unsolved missing-person cases than any other location on Earth -- more than 20,000 people have vanished in the area in the last 50 years. There are a number of theories about what causes the disappearances, ranging from local predators to the rugged, dangerous terrain. A team of investigators works with local experts and eyewitnesses to try to solve the mysteries. They gather evidence, conduct tests and explore local myths to try to determine the most viable explanation for each case they explore.