Australia's northeastern coast is a hotbed for shark activity. Its tropical seas are home to more species of sharks than anywhere else in the world. But there's trouble in the sharks' stronghold Down Under – even here the sharks are disappearing. What's happening to them? A special team made up of pioneering Australian marine biologist Richard Fitzpatrick; noted shark documentary filmmaker and host Mike deGruy; lead scientist for the Nature Conservancy M. Sanjayan, Ph.D.; and adventurer Celine Cousteau band together to find out, while undertaking the largest shark tagging expedition in Australian history. Their mission: to discover the cause of the mysterious decline in shark populations here, and find out if we can help the situation. To do so, the team deploys underwater animal cams and remote cameras to explore and record shark behavior and to gather new insight into the still largely secretive life of the ocean's ultimate predator.