Scotland, shut off from the rest of the world for 30 years due to a deadly virus is now the focus of interest because the virus has now broken out somewhere important (London) and they have spotted a lone Survivor from satellite and reckon a few may have survived the virus and be immune, hence a cure. Q a mission to collect a survivor. After a trip thru the wall they find Glasgow literally stuffed full of rejects from Mad Max Beyond Thunderdome that for some reason are cannibals, despite Scotland being full of cattle, all sporting pink spiral Mohawk hair and a liking for leather fetish gear in a kinda 1980's Hollywood comedic scarey punk guise (I live in Glasgow and anyone dressed like that would freeze no matter how big a pink Mohawk they had) the heroes are captured. It's at this point Sean Pertwee looks relieved that they cooked and ate his character, just to get out of this awful movie. Even The Gimp from Pulp Fiction makes an appearance.
Finally they escape in the Hogwarts Express only to be captured by a bunch of rejects from Excalibur. They then escape in a fully working Bentley that's been locked in a nuclear bunker for 30 years and have a final showdown with the Mad Max rejects. Then all, apart from the female hero, fly off in a helicopter to safety. Why not just land the helicopter in Glasgow in the first place, grab the 1st mad Max clone that shows up and spare us this ramshackle genre confused carry on? Leave your sensible head somewhere else and don't expect Citizen Kane. As a fun B movie this works. At best this is entertaining as it's just so laughable.