CONSIDER THE MOST unlikely elements you can conceive of for a novel. Take the fact that the here is a teenaged loner, a high scheel student nicknamed Birdy. Add the reason for his nickname: he is enamored at first of pigeons and then, more enduringly, of canaries. Realize that Birdy's absorption in aviary life is so absolute that nothing else in his existence matters to him, neither girls nor school nor male companions. Allow him one exception, a friend named Al, a jock, Superboy sports competitor who to some small extent at first shares Birdy's preoccupation, or at least is willing to listen to him as he expounds learnedly on the subject.

Birdy's obsession advances into all the details of cage-building and breeding, feeding. It culminates in his falling in love with the female canary he names Birdie; later he transfers his love to another extremely comely bird, Perta. Once he has fallen in love, Birdy seeks to learn Perta's language, watching her every move (including the intimacies of her bowels) for hours until he feels so clost to her that he is "caged out of her cage." He begins to think of himself as a giant bird, buil is a nest in his room, and plans his aerodynamic efforts. People shouls be able to fly, he thinks. The trouble is, "They don't want to hard enough."

All this time he is determined to conquer the art of ornithoptery, making for himself giant feathered wings and devising ways to adjust his body to the properties of air and to the art of flying.

Birdy's view of birds is reminiscent of Mrk Twain's. They are preferable to humanity. "I don't even want to look at people. People cna be so gross, especially grown-ups. Theu grunt and groan, make swallowing and breathing noises all the time. They smell like putrid meat. They crawl around with heavy movements and stand as if they're nailed to the ground." Birdy's enemy is his mother who hates his birds, thinks them dirty, noisy, unhealthy. Birdy does everything he can think of to placate her: "I don't want any trouble, that's all."

These progressively absorbing ornithological details (reminiscent of the fascinations of Melville's cetology in Moby-Dick ) are interlarded with chapters, which take place in a mental institution at the end of World War II. Birdy, a psychic victim of war, perches in his cell in avarian posture. Ha! you say, I knew it. Where else could all this nonsense be happening? But you are wrong. Birdie is as mad as Billy Pilgrim, the hero of Slarghterhouse Five , like him a victim of the appaling vision of war. Birdy's old friend Al, his face badly damaged by a shell and about to undergo plastic surgery, has been brought from his hospital to Birdy's to talk to his friend in an effort to bring him back from his apparent disconnectedness to sodden reality.

Birdy appears mad because, having once given his entire faith to his world of credible birds, he now "can't believe anything any more." In this odd sense Birdy is in part an anti-war novel. Birdy has been made mad by the war in which Al has lost part of his face. In the context of a world at war, Birdy's ovsessed adolescence is sane by contrast with Al's memory of his part in the attack upon the Siegfried Line: "We all have our own private kinds of craziness."

(This is the only element in this long and beautifully crafted novel that I found unconvincing. The qar, while graphically described, seems an afterthought of a device rather than an integral or inevitable part of the story.)

The novel's crisis occurs during one of Birdy's adolescent dreams. In the dream he becomes a bird, marries sterile Perta, fertilizes her, and begins to raise their children. The dream is a continuous one, continued from night to night and vivid to him during the day. At one point reality and dream almost fuse, and Birdy's monomania reaches its nadir.

Unlikely? Foolish? Unbelievable? Not at all. Birdy is an extraordinary achievement. Wharton, whose first novel this is, provides all the proper ingredients for creating belief in the reader. The details are introduced slowly, cumulatively. They are, apparently, based on sound factual material (or so it seems to the uninitiate in bird lore). The boy's adolescent voice, instructing us in what he knows, what he finds out, is cerebral, clear, personal, and altogether convincing.The situation, on the face of it absurd, thus becomes credible and engrossing. We do not need to suspend belief. We do, strangely enough, believe .

Put all this together. Accept the fact that the final pages resolve Al's and Birdy's lives in the sanity of acceptance, Al because he has survived the war, even at great cost: "I lie there with my eyes closed, listening, thinking about how I'm out of it. I'm out of everything, not just the war. I'm captured; the world's prisoner. I'm not fighting any more." And Birdy because he sees that "we really are loons. We're crazy because we can't accept the idea that things happen for no reason at all and that it doen't mean anything." Together they plan two equally mad escapes for Birdy from his loony bin: " 'And, so what hapens then? ' 'Nothing' Al., just the rest of our lives.' "And Al asks:" 'Is that all?'"

And what you have here is an uncommonly good novel by a novelist whose promise is established with his first effort.