Retromancer - Robert Rankin

There is big and evil magic abroad upon the face of the Earth. History has been changed. The Germans have won WWII. America is a nuclear wasteland. And worst of all, the breakfast menu at The Wife's Legs Caf? in Brentford is serving Bratwurst rather than the proper big boys' British banger. Something is Not Right.
And when the world's all wrong and it needs setting right, who're you gonna call? Hugo Rune, that's who. A man who offers the world his genius, and asks only, in return, that the world cover his expenses.
And so, with the aid of his faithful acolyte and companion Rizla, the guru's guru, also known as the hokus bloke, the Lad Himself and the Retromancer*, sets out to rewrite history the way it should be.
Together they return to war-torn London, to solve the twelve cosmic conundra based on Hugo Rune's personal tarot deck, each one leading them closer to a final terrifying confrontation. They must match their wits against beautiful spies, advanced alien technology, killer robots and death rays, do battle with an ancient god, and come face to face once more with Hugo Rune's arch-enemy, the sinister Count Otto Black, all the while finding time to drink ale, talk the toot and dine out in some of London's swankiest eateries. Without ever paying the bill.