PERFECT GALLOWS By Peter Dickinson Pantheon. 233 pp. $16.95

MORE OFTEN than not, Peter Dickinson's novels edge furtively around the mysteries at their cores, afraid to commit themselves, as if the author knows that the gold settings are more valuable than the murderous jewels themselves. Again and again, he builds ornately detailed, frequently amusing or simply bizarre worlds which in and of themselves operate on a level of tedium that lulls one, bores one to within an inch of simply flinging the book aside. And then, at the last moment, when the novel is almost stone dead, things begin to happen: you begin to understand what the hell you've been reading about and why. It is a perilous, irritatingly elliptical way to construct novels but Dickinson has pulled it off fairly frequently.

In Perfect Gallows he once more deals with a shifting minefield, superficially peaceful, moving to and fro through time -- the D-Day summer of an English teen-ager facing the call-up, and the middle age of the famous actor he's become 40 years later. The novel centers on Andrew Wragge, who becomes the actor Adrian Waring that summer, at 18 playing Prospero in a theater-loving relative's amateur production of The Tempest. And to the extent that it is Andrew/Adrian's novel it is about a monster. He is consumed by his utter solipsism: his life is all that matters, his wishes, his ambitions, his will. For him there are no second choices.

Andrew/Adrian is as cold and calculating a customer as you're likely to stumble across, even in Dickinson's work, which tends to abound with remote, or very well-distanced, characters. In this instance, the lad's mother's death in the Blitz serves merely to free him from family demands that intrude on his overwhelming egotism; a good-natured offer of financial aid from a relation is thought to be an effort to control him; he intentionally enrages an ancient tycoon who dies on the spot of an apoplectic fit; he carries out the remarkably passionless seduction of a sweet young girl and leaves her with the consequences . . . and 40 years later he is mindlessly cruel to another young woman who loves him.

The problem inherent in such a situation is that not only does one not give a fig regarding the fate of our tedious thespian: one actually longs to see a stake driven through his mean and shrivelled heart.

And speaking of hearts, the mystery at the heart of Perfect Gallows is twofold. There is the murder of the only charismatic character in the novel, an elderly African servant whose sense of honor and integrity and loyalty outfit him inadequately for the spot of bother that undoes him. And, a` la Josephine Tey's Brat Farrar, there is the return to the family castle of an amnesiac heir who may or may not be the genuine article. These two threads of the piece finally intertwine in a satisfying, albeit obvious manner.

BUT DICKINSON has no real interest in the "mystery" nature of Perfect Gallows. Presumably he is interested in the obsessive psyche of Andrew/Adrian, though as obsessions go his is one of the less interesting -- the sheerest self. Andrew/Adrian is, in fact, a man only his shrink could warm to.

What surely is uppermost in the author's mind is the depiction of both the Wragge family and the country gentry during the war. In both instances he is at his descriptive best; the time and place and people come briefly alive, as they might in an ably written memoir. In the end, what has gone wrong is the rangefinder through which we view the goings-on -- the eye of the jumped up little squirt who becomes Adrian Waring. He and his skimpy soul loom too large while everyone else is left deserving more time at center stage.

Since the conventional mystery aspects of Perfect Gallows create so little suspense, one wonders why they are there at all. Of course they are there to cast light on the degrees of Adrian Waring's monstrousness, the one thing we know a good deal more about than we care to. He is a truly hollow man and, unfortunately, the novel captures his essence.

Thomas Gifford is the author of "The Wind Chill Factor" and "Hollywood Gothic."