From the guy who did Dog Soldiers & The Descent.
Scotland has been wiped out by a deadly virus, & walled off from England.
30 years later, the virus appears in England, so a team heads over the re-built Hadrian's Wall to Scotland to try & find a cure, while battling crazed survivors, freaky street gangs, & weird medieval societies.
http://en.wikipedia.org/wiki/Doomsday_(film)