IN this account of Adolf Hitler's origins, Norman Mailer has hurled the products of his imagination and his research into the black sky of the past, where they swing, as on a literary gibbet, in bold and colourful relief, to horrify and entertain us.

It is not a history book. A true historian collects, selects and combines facts to compose his picture.

Mailer followed that rule to some extent, but he also bent, stretched and dressed it with extravagant surmise and unrepressed glee.

This is a vivid, eye-popping novel in which history throbs but fitfully, the devil enjoys a dominant role and the stream of narrative flows deviously over the jagged rocks of human mischief. Which is precisely the author's purpose.

There is an old German saying, "BA ser Vogel, bA ses Ei" (A bad bird lays a bad egg). The bad bird here is the coupling between a father and daughter that created the bad egg: Hitler. Which prompts another proverb: "Ein faules Ei verdirbt den ganzen Brei" (One bad egg spoils the whole pudding). Few within memory of the Third Reich, the second world war and the Holocaust would argue with that.

What force created the bad bird and its bad egg? According to Mailer, it was our old acquaintance the devil, one of whose minions, SS officer Dieter, assumes the part of narrator with a view to improving our "impoverished understanding of Adolf Hitler's personality".

Hitler is Dieter's "client": "I followed his life from infancy a long way into his development as the wild beast of the century, this alltoo-modest-looking politician with his snippet of a mustache."

The information Dieter relays to the author is intimate and occasionally confusing. Adolf 's father, Alois, tells Adolf 's mother Klara that she is his niece, whereas she is his daughter. When she goes to bed with him he says: "I am your very bad uncle." Orgasmically, she gasps: "Oh, we will be punished!"

However, it's the devil who made them do it, for he is in charge of all destinies here, especially those of a pornographic nature.

Thus, "Klara turned head to foot, and put her most unmentionable part down on his hard-breathing nose and mouth, and took [Alois's] old battering ram into her lips, " only to find it "as soft as a coil of excrement". Later, when Adolf is born, she keeps to her own side of the bed and, perhaps to keep her pretty mouth busy, bites her husband/dad on the wrist. It seems Hell hath no fA1/4hrer like a. . .

Not to worry, for the devil steps in again, to let us see Alois "burying his nose and lips in Klara's vulva, his tongue as long and demonic as a devil's phallus", and to introduce us to the infant Adolf smearing the family sofa with his (what else? ) excrement. If the descriptions seem over the top and under the bottom, remember, it's not Mailer who's pumping out this stuff - it's Dieter, the devil's agent, who also reveals that Klara, when cleaning Adolf 's posterior of yet more excrement, comes to notice that the three-year-old "had one testicle, not two". It is at this point in Dieter's narrative that a song from my school playground came to mind. It goes: "Hitler had only got one ball. Goering had two but they were small. Himmler had something similar, but poor old Goebbels had no balls at all."

We're not told if Hitler's attitude became lopsided as a consequence. We do learn that, aged nine, he developed a burning hatred for a long-nosed priest who caught him smoking; that when Alois whipped him it fortified Adolf 's "will of iron", even as it satisfied Alois's desire to fondle the boy's buttocks;

that he liked to sit on a cemetery wall at dusk and shoot rats as they emerged; that he upset his teacher by quoting the Bishop of Cluny's phrase about us all being born "between piss and shit".

Near the end of the book, Dieter mentions that "I was witnessing a comedy". Suddenly, my playground song ceases. For the remaining chapters another insistent refrain intrudes: "Springtime For Hitler and German-ee."

Thank heaven for musicals!

They too may improve our "impoverished understanding" of things.