One of the world's experts on hammerhead sharks, marine biologist Pete Klimley is fighting the stereotype of sharks as primitive and vicious killers. In fact, hammerheads exhibit some remarkably sophisticated social behaviors, including their schooling in the hundreds at underwater seamounts in the Pacific Ocean. To tell the story of these incredible animals, author Ken Mallory talked with Pete Klimley and then traveled to tiny Cocos Island, 330 miles off the Pacific coast of Costa Rica. There, he had the chance of a lifetime to see these awe-inspiring animals up close.