Hermetically Seared : MAO II, <i> By Don De Lillo (Viking: $19.95; 238 pp.)</i>

In Yankee Stadium, 13,000 followers of the Rev. Sun Moon are being married by their master. The most personal of rites is turned into an avalanche of polyester suits, cheap bridal gowns and tired young faces; into a mass ceremony with a militant collective purpose.

Outside the stadium stretch hundreds of acres of tenements, burnt out, ruled by drug gangs and squatted in by fragmented families--a sample of the world’s collective despair wedged into upper Manhattan. It is a second mass phenomenon, this one chaotic and purposeless, but in some obscure way the reciprocal of the fanatically organized energies inside the stadium walls.

Mass purpose, mass dereliction; each is a threat to and in some way a consequence of a third Manhattan. The one where people go to work, go shopping, juggle with debt, personal safety and a suppressed fear of disintegration, all the while, struggling to think of themselves as Western individuals with private choices. As Don De Lillo writes in his new pre-Doomsday novel:

” . . . people ride escalators going up and sneak secret glances at the faces coming down. People dangle tea bags over hot water in white cups. Cars run silently on the autobahns, streaks of painted light. People sit at desks and stare at office walls. They smell their shirts and drop them in the hamper. People bind themselves into numbered seats and fly across time zones and high cirrus and deep night, knowing there is something they’ve forgotten to do.

“The future belongs to crowds.”

The mass wedding is a prologue to “Mao II,” a novel about the crowds of our times, their manipulators and various individuals who struggle among them. They struggle, that is, like fish in an industrially polluted stream, with convulsive movements and a clouding eye.

There are the Moonies and Karen, a young upper-middle-class woman who joins them, leaves them and never is free of them. There is an Arab terrorist organization of hooded youngsters who unquestioningly follow a middle-aged Mao-like “father,” and the Swiss poet who is their hostage. There is a different kind of crowd, with a different kind of manipulator: our own society, with financial and publicity mechanisms, whose purposes are as bottom-line as Mao’s; and an admired, embittered and would-be-solitary novelist, whose solitude and art are made into a commodity and poisoned.

Bill Gray, variously suggestive of J. D. Salinger, Thomas Pynchon and Harold Brodkey, has written two brilliant novels that have achieved cult status. He has secluded himself, shunning all interviews and outside contacts. A formidable expectation has built up around this seclusion, especially since it has been years since he has published anything.

Brita Nilsson, a famous photographer of great events and calamities, penetrates the seclusion. Weary of the great-event game--everything has become publicity--she seeks the authentic. Perhaps she will find it by photographing nothing but writers; if these aren’t private and authentic, who is? Nobody is more private and, presumably, authentic, than Gray.

She is contacted by Scott, Gray’s assistant and acolyte, and spirited in secrecy to a backwoods home. There she finds not the Wizard of Oz, but a lonely, talkative, sad-faced man with a bad stomach, smoker’s lungs and no magic in him. Every scrap he had ever written or received is archived around him in a kind of bunker--Scott, assisted by the ex-Moonie Karen, who sleeps alternatively with him and his employer, is sedulous and methodical. Gray has finished a novel but he knows it’s heavy, static and self-conscious. He keeps working away, not in hopes of improving it but because he is trapped.

He had isolated himself as a simple artistic reflex, looking for peace and the opportunity to work. But the media have seized on this isolation, made it into a myth, given it the most devastating celebrity, and set up a disabling public expectation. He wants to deflate the pressure; perhaps Brita’s photographs, released bit by bit, will do it. Perhaps he can come out of seclusion, eat at restaurants, recover some of the naturalness. “Remember literature, Charlie?” he asks an old associate later, when he comes to New York. “It involved getting drunk and getting laid.”

Gray’s paralysis goes beyond isolation, adulation and beleaguerment. There is a feeling of uselessness. The novelist has become irrelevant and no longer possesses the power “to alter the inner life of a culture,” he declares. The world is organized and manipulated in crowds; the novelist’s transforming influence has been taken over by terrorists: “The danger they represent equals our own failure to be dangerous.”

Charlie, now a hotshot publisher for a big international conglomerate--”It’s all about limousines,” he explains--has just the thing for him. A new Arab terrorist group has sprung up and kidnaped a Swiss writer. A new publishers’ group also has sprung up. Both need publicity. The publishers will issue a public appeal, the Arabs will make a public gesture, and everyone will benefit. And if Gray appears at the press conference--”Recluse Speaks Out for Prisoner”--it will be a smash hit and, incidentally, drive up the sales of Gray’s book, which Charlie is determined to acquire. There will be no problem, of course, in breaking “the crumbling remnants of a contract” with Gray’s “old, dusty, lovable skinflint house.”

Escaping his obsolete calling, Gray tries to deal with his activist successors, the terrorists. After a series of cloudy encounters, a bombing and a trip to Greece, the negotiations collapse. Far from being “novelists,” the terrorists are one more group of corporate maneuverers. Gray, increasingly unhinged and ill with cancer, makes a valiant but ignominious ending.

De Lillo writes with characteristic corrosiveness and wit. Like his previous sorties against the dismay of our times, “Mao II” is winged and agile, flying us to odd and seemingly unreachable vantage points for a view that would be purely chilling if we didn’t feel so exhilarated at getting there to see it.

The description of Karen’s life among the Moonies--”Prethink your total day,” a supervisor tells the pencil-selling initiates. “Then jump it. Jump it. Jump it”--is baleful and arresting. So are the marks of servitude that remain after she escapes. “I think we ought to have our intercourse now,” she tells Gray, after putting him to bed.

De Lillo’s satirical portrait of a modern publisher is wickedly satisfying, and his talent for moral suspense, reminiscent of Graham Greene’s, makes a splendid portrait of the ambiguous Arab intermediary between Gray and the terrorists. And nobody, of course, is better placed to write about the poisonous exposure and solitary agony of the contemporary writer.

Perhaps, in fact, De Lillo is too close. The scenes with Gray, particularly in his retreat, bog down in their very intensity; besides the portrait of a writer immured inside himself and going dry, they suggest a confessional. There are times when we wonder whether Gray, lamenting the inertness of his book, is not De Lillo foreshadowing what we shall find in parts of his. For much of the time, it is as if the author’s corrosive voice had begun to eat at itself; as if darkness had swollen to blot out the contrasts--De Lillo’s talent for a fugitive tenderness, the slapstick shuffle in his funeral marches--by which darkness can be made out.