Doomsday takes place three decades after a lethal virus called the Reaper nearly wipes out Scotland and causes the rest of the world to wall off the country. When the Reaper begins to emerge in another country 30 years later, an elite team and their leader (Rhona Mitra) are sent to the contaminated landscape of the walled-off country to find a cure.

http://en.wikipedia.org/wiki/Doomsday_%28film%29