Ah, the London Underground: overcrowded trains, endless signal failures, an enormous slumbering dragon. What? Dragon? That would be the sleepy beast one little boy unfortunately awakens while visiting his engineer mum who's building the Jubilee Line extension.
Jump forward two decades and one big mother of a dragon has reproduced, razed most of the planet, and driven what's left of the human race into hiding.
At a castle-cum-shelter in Northumberland, the little boy has now grown up into the bitter and bearded Christian Bale, leader of a small band of survivors who never quite know where their next meal, or dragon attack, is coming from.
It's looking pretty grim for everyone, and even more so when Matthew McConaughey - a bug-eyed Yank called Van Zan - turns up from across the pond boasting that he's going to save the day.
He and his tooled-up gang claim to be dragon slayers and are out to rid the Earth of these fire-breathing fiends. God bless America.
What should be a load of utter rubbish is actually surprisingly entertaining. Laugh at Bale's hardcase English accent (not to mention some of his lines); don't be intimidated by McConaughey looking like a cross between a WWF wrestler and Dennis Hopper in "Waterworld"; and marvel at the totally fantastic looking CGI dragons and some rather nifty action sequences.
With over 30 episodes of The X Files under his belt, director Rob Bowman was perfectly placed to take on a very bizarre premise and make it appear possible.
The grimness of the wiped-out world is offset by the campy posturing of a tattooed McConaughey, and while Bale is earnest as the guilt-stricken leader Quinn, he also gets the best "Star Wars" gag you'll see in years, distracting the ragamuffin kids from the misery of their predicament.
And it's hard not to like a film that has sky divers jumping out of helicopters to catch flying dragons in a big net.
With cartoon heroes (is ultra-buff McConaughey the new Stallone or the old Vin Diesel?), swooping dragons, and a burnt and blitzed London climax, this could well be the best barbeque you go to all summer.