By Patrick McGrath

Poseidon Press. 204 pp. $18.95

THERE is a trick at the heart of Spider -- a trick that only a dastardly reviewer would reveal -- but the beauty of Patrick McGrath's writing is that it does not feel like a trick. Rather, as we gradually begin to understand the way in which we have misunderstood the book's circumstances, what comes out feels like the inevitable truth. It was only our own desire to be deceived that allowed the trick to work.

The eponymous narrator of Spider (he tells us it's a nickname his mother called him) is one of those creepily congenial fellows so familiar to us from the work of Edgar Allan Poe, Paul Bowles and Ian McEwan. There is method in his madness, and both the method and the madness appear in his writing -- are, indeed, the causes of his writing. For this document which we have before us is simultaneously a confession of murderous hatred, a tissue of self-deceiving lies and the therapeutic act of a recently released mental patient.

The writing is what keeps Spider alive, but it also allows him to remember things that make him want to die -- things about his life with his parents in Kitchener Street, and the suspicious death of his mother. "And with that thought," he tells us about one such memory, "unless I was careful, such a flood would be set roiling and seething within me that at times it was your old Spider who got trussed up in canvas webbing and marched off down to a safe room (his head twisting to escape the smell of the gas)! But in time I learned that there were ways of thinking about Kitchener Street and the tragedy without losing control (it all has to do with compartments) . . ." "Roiling and seething" versus "thinking" and "control" -- those are the extremes that shape Spider's sentences as well as his life.

McGrath's narrative (as opposed to Spider's) works on a number of levels at once. There is the present situation: Spider (whose real name is Dennis) scribbling at his little desk in his halfway house, or taking uncomfortable walks along the canals, bundled up in more clothes than a normal person would wear. Then there is the past, which reaches us in accumulating fragments as Spider sets down his memories.

At this point McGrath's narrative and Spider's begin to part company: we have only Spider's writing to go on, but we begin to see around it to the real situation. And then there is the "future," if one can call it that -- the heavy note of foreshadowing that rings throughout the book, in such remarks as: "But it's strange that I should have liked the cellar, because that's where he belted me. I remember once (I'm not sure if it was before or after my mother's death) . . ."

Beyond that, there is the level of literary allusion, of authorial games. Spider would naturally like the cellar because he is (what else?) a spider: That's how he views the hidden self who scurries away and hides inside "Dennis" whenever the psychiatrists try to probe. Spider's father drinks at a pub called "the Rochester" -- famously, the name of the man in Jane Eyre who kept a mad wife hidden in the attic. So far, we're within the realm of the remotely possible, in that a writerly madness like Spider's might closely resemble the allusive punning of a clever author. But then we get something like this remark about Spider's father: "A new sort of anger burned in him, and it burned with a cold, hard, gemlike flame." What in the world is Walter Pater doing here? As an allusion to the book's theme of madness, Pater fits in (since his esthetic theory elevated the non-rational, romantic, "crazy" passions); but as a fragment of the relatively uneducated Spider's memory, he doesn't seem quite believable.

Still, such lapses are only occasional. For the most part, Spider's tale has the compelling quality of felt reality. This is particularly true of his dreams, which have the wonderful richness of Freudian case-examples and nonetheless feel like real nightmares. Take, for instance, his dream about a seal: "I was standing close to the edge of the canal as a skeleton surged up from the water, carried on the back of a wave, a skeleton housing some sort of sleek, seal-like creature squeezed tight within its rib cage. The whiskered snout of this awful black lumpy thing was pushed out from between the bones, and it exposed a set of tiny teeth as it bleated pathetically at me . . ." As Freud would have been the first to point out, the word "seele" is German for "soul" -- and what is Spider's soul, in his own view, but an "awful black lumpy thing" that's trapped within an imprisoning skeleton? To free it from this prison becomes his major effort during the last part of the book.

Spider is a thriller, of sorts, as well as a psychological case study and a gem of self-conscious prose. The only thing it lacks, to give it true thriller status, is the thrill of terror. Despite the horrors decribed in Spider's controlled-maniac voice, we never really feel horrified; our admiration is purely cerebral. I began by comparing McGrath to Poe, Bowles and McEwan, but the comparison is not accurate in one respect: All three of those writers know how to terrify us. A recent reviewer described Ian McEwan's latest book as the work of "a Stephen King who has learned to write like Henry James." McGrath has almost mastered the Henry James part; what he needs to do now is to go back and pick up the Stephen King.

Wendy Lesser is the author of "The Life Below the Ground" and the forthcoming "His Other Half: Men Looking at Women Through Art."