The island of La Palma, off the northwest coast of Africa, is the picture of tranquility. La Palma's beauty however belies a hidden danger -- a secret threat that two scientists suspect could forever change the world. Investigators Simon Day and Steven Ward believe that the island of La Palma may someday trigger a tsunami the likes of which no human has ever seen - a mega-tsunami. It's a controversial theory, but Day and Ward stand by their research. Follow them as they gather evidence to support their case on the island of La Palma - from caves harboring cryptic clues to dramatic craters and computer models. According to their research, under the worst-case scenario, a massive chunk of La Palma could break free and plunge into the sea-spawning waves that could rip across the Atlantic at staggering speeds and destroy coasts from Canada through the United States, the Caribbean and all the way down to Brazil.