Investigating the series of explosive fires that ravaged pig barns across North America.

A mysterious pack of blacktip sharks has arrived off the eastern coast of South Africa, taking charge of the reef and antagonizing local fisherman. Shark scientists are stunned. Normally sharks are loners, but it seems that this group may be organized. What's behind this unprecedented behavior and what brought the gang to these waters? Take the plunge with dive boat operator Mark Addison as he swims with sharks, tries to study their pack mentality, and makes discoveries that could inspire a new realm of shark research.

Game wardens at Periyar Wildlife Sanctuary in South India are horror-stricken when they discover dead female elephants littering the once peaceful 350-square-mile block of land. The cause of death isn't clear: one has a mutilated trunk, two have head injuries, and one has a shattered jaw. Local conservationists are forced to become investigators, but they are running out of possible explanations for these mystifying deaths. Can they track down who or what is killing these gentle giants?

In 2001 biologists in Australia's island state of Tasmania found that the Tasmanian Devil, an iconic species unique to Tasmania, was afflicted with a new, fatal kind of cancer. The mystery was how thousands of Tasmanian Devils could have the same cancer at the same time.

On April 16th 2006 an American sports hunter, Jim Martell from Boise, Idaho, happened upon the rarest bear on earth. Martell had purchased, for forty thousand US dollars, the right to hunt on remote Banks Island, high above the Arctic Circle.