Larry Sullivan is a white collar FBI agent, but when a mysterious virus strikes on board a cruise ship he's send to his uncle John, a recluse who shoots at strangers, but one of the last surviving experts from the 1960s programs to develop biological weapons. He and his Russian-born old friend Yuri Zenkovsky confirm it's a variant of the extremely contagious and deadly Marburg virus, which was made as contagious as influenza in order to wipe out most of a continent's population if spread from four strategical points, and soon it is at three; the North American dead-count rises exponentially...