The hammerhead shark is one of the recognizable animals on planet Earth. But very few people know that it is also one of the most highly-evolved and specialized predators ever. Dr. Neil Hammerschlag and his team of researchers are setting off on a quest to learn more about this mysterious shark, as well as search for the most elusive of them all -- the massive Great Hammerhead -- a shark that can grow up to 20-ft in length and can weigh over 1000 pounds.