Imagine a flu that kills 70 percent of those it infects and has the potential to become as contagious as the common cold. Would a wide spread panic break out? Would martial law have to be imposed? Would the global economy come to a halt? These are only a few of the concerns surrounding a deadly strain of avian influenza that first made news in Asia in 1997. Join National Geographic as we follow a swat team of virus hunters and the worl