Battle of Scotland

It is the year 1948, and finally the long awaited Frialus Virus has managed to cross over into the British isles through Ireland after seemingly being quarantined to mainland Europe, and now it has completely overrun the south with the royal family and Churchill being evacuated north for a rendezvous point with the navy. In order for it to be done, the collapsing remnants of the British army have made their final stand in Scotland, joined with Commonwealth forces and some allied nations like the United States, Mexico, Brazil etc. As the dead close in, the last battle must begin.