STUCK IN its groove, the new cockpit hood of Flying Officer Hillary's Spitfire will not budge. He and a ground crew work away with files and oil, but the hood slides only half-way when the order comes for Squadron 603 to scramble. A corporal crosses his fingers as Hillary taxis off.

Half an hour later the cockpit is aflame. The hood jams. Hillary tears off his straps, frees the hood, passes out, and comes to at 10,000 feet after falling out. He tugs the rip cord, and parachutes toward the sea, where, afloat in his life jacket, he notices dead white skin coming off his hand. His lips bulge like tires, but soon he cannot see them at all, having gone blind. He loosens the valve of his Mae West so as to drown, but the chute buoys him up, and he starts to laugh, hallucinateand dream. Hours later, the Margate lifeboat finds him, and as he thaws he begins to feel all of the pain of his burns. His agony, not that he calls it that, has only just begun.

All this happens in the six-page "Proem" or preface to The Last Enemy, first published in 1942 (in the United States as Falling Through Space) and now revived (by St. Martin's, $5.95) as a classic of air warfare deserves to be. But the book is more than that, revealing how a smug and supercilious Oxford dilettante became a connoisseur of mortality, an authority on the softness of human meat in a world where the forces of "anti-life," as he called it, outdo those of good. He comes through as an absurdist of the dogfight, a silver-spooned baron of battle reduced by pain and rage and grief to the random guesswork of a pagan child. He yearns to get back into the air and shoot down more Huns, and he wants to write about not quite knowing what else to believe in; but he is dead at 23, himself shot down with his problem unsolved.

This is less a book based on tranquil recollection than it is a severe conspectus assembled during convalescence from heroic bouts of plastic surgery. Indeed, his convalescence ended only with his death in 1943. There was so little time. The Last Enemy quivers with fateful twists. On the last page he decides to be writer, but he has already finished his only book. The Proem coming first, feels written last, then put up front as the stark premise to a flashback reconnaissance that catches up with itself at chapter six; you have to wait a hundred pages to see what happens after they get him to hospital and administer painkiller. In the Proem he harks back to one of his early short stories in which the hero, having fallen from an ocean liner, calls for help (like Hillary in the North Sea) with a lone seagull for company.

So The Last Enemy, drafted as preliminary to a book that would really count ("I would write of these men") ends up as The Last Book, an unintended terminus, and Hillary's beau geste of flying against the Luftwaffe again, with ruined face, becomes a nonverbal epilogue. Nowhere in the book does he mention its actual writing under what must have been terrible circumstances, just as he never reveals what subject he has been studying at Oxford.

Here is another of those documents from within the inferno which bring into our ken almost unthinkable dimensions of reverse response: beyond hatred of suffering to hatred of sufferers, beyond hatred of evil to hatred of humanity itself, and beyond hatred to ecstatic paralysis. No wonder that Ernest Gann in his foreword to the St. Martin's edition, aghast at what Hillary endured as his face and hands were put together again (more or less), coins the phrase "the absolute rectum of despair."

Once read about, the eyes caked with gentian violet do not go away. Or the nurses who faint while changing his dressings. Or the beetles that seem to run down his face. Or the bloated prosthetic lips. Or the complex deliriums in which bacon, streptococci, Mercurochrome, eau de cologne, and exposed bone provide a context for the howls of a young girl. He dare not blow his nose lest he puff his grafted lip away. His arm, where the new lip came from, splits open like a fan, "exposing a raw surface the size of a half orange." A thin steel probe clears the hole behind his ear for drainage. The rest is septicemia, suppuration, Protonsil, and cold brown tea. His skin green-blue, Hillary ponders Charles II's apology for being such an unconscionable time dying.

THEN, SUDDENLY, he is out and about in his beloved London among crocuses, thinking up a play to be called Dispersal Point. A bomb falls. He helps to pull a dead child from the rubble. "I see they got you too," the mother says, then dies. "I wanted to seize a gun and fire it, hit somebody, break a window, anything. I saw the months ahead of me, hospital, hospital, operation after operation, and I was in despair." The reprieve of spring is over.

Vivid flying scenes counterpoint this calvary. The engine quits on his first solo cross-country, and again on his second. He learns that most Messerschmitt 109s execute a half-roll, and a dive, when attacked from behind; that a Spitfire's propeller is long and must be kept clear of the ground on take-off; that the recoil of eight machine guns cuts his speed by 40 miles an hour. And above all he learns "the uselessness of all aerobatics in actual combat." By choice, with known consequences, when he flies he wears his goggles up. His plane he calls Sredni Vashtar, after Saki's ferret: "His enemies called for peace, but he brought them death." He shouts German invective over his radio at German pilots, one of whom answers. At night he switches off his mind "like an electric light," but never in this mesmeric, death-laden, self-censuring book, in which, as an Oxford hearty, he rows in Germany against Hermann Goering's prize crews, and, only a year later, flies against their aerial counterparts at 30,000 feet. The prose often makes one pause while the gathering small sum of Hillary's days, 365 times 23, streaks through it in headlong, honorable charge.

Rereading him recalls for me the time when, as a green young flying officer, not long "down" from the same university, I presented myself to the adjutant at the RAF base I had been posted to. He showed me one of those yard-wide group photographs, this one of buoyant young pilots all wearing their new wings. As far as he knew, he said, he was the only one of them still alive. I mentioned Hillary's book, and he said he knew it well. Yet, oddly enough, in the ensuing years, in all my conversations with scores of Battle of Britain and Bomber Command aces and heroes, I never heard Hillary's name again. They were more at ease talking about Johnnie Johnson and Douglas Bader, perhaps because Hillary comes too near the bone, goes beyond aerial exploits toward an unknown region of Being and Nothingness in which all humans soner or later earn a battle ribbon. Hillary, the premature complete existentialist, versed in French and German traditions, and spouting Donne, Verlaine, Goethe, Newton, Leonardo, Auden and Isherwood, Pound and Eliot, was too much of an intellectual without ever being in any sense academic.

As J.B. Priestley pointed out in a review of The Last Enemey that appeared promptly enough for Hillary to see it, the RAF prefers its heroes inarticulate, almost as if taking a hint from Erasmus ("of those that are slain, not a word of them"). Unable to countenance Hillary the idea-man, his contemporaries and successors also missed the spectacle of the man of ideas ultimately not knowing what to think. For Hillary the mind was no better a problem-solver than the Spitfire was a night fighter -- "the flames from its own exhaust make the pilot's visibility uncomfortably small." To read Hillary now is akin to reading Gide or Camus. How un-English he became before his flame went out. He belongs to literature and not to any flag. The last word in the book is "civilization," and Hillary knew that it did not mean a feeding frenzy, although it often looked that way. Death, as his epigraph from Corinthians XV, 26 asserts, is the "last enemy," but, as his book reveals, there so many other enemies distracting us from it. That is why they exist. Aching to kill death itself, he died to kill its ghouls.