WILLIAM TREVOR (Cox), 54, an Irishman fromCounty Cork now living in London, has in eight novels, four story collections, and numerous plays and BBC programs, built a reputation for laconic prose and understatement which compact, even pressurize, the large themes he prefers.

"I am for protest and misbehavior," he once told an interviewer for London Magazine --probably in a quiet, polite voice.

In exactly that voice here are 12 stories which introduce seemingly quiet, polite people, present them in low-key, well-crafted prose, then transpose both characters and plot into something more, something else, usually something far worse.

The title and longest story takes four Britishers "beyond the pale," not only to confront protest and violence in modern Ireland but also to catch them outside other pretenses within which they have fenced their neat, safe lives. The historic "English pale," an enclave in Ireland which lasted from the 1170's until the country was subjugated under Elizabeth I, has its counterpart for Dekko, Strafe, Cynthia, and Milly, all Londoners. Their "pale" is a pleasant seaside inn in County Antrim where since 1965 they have spent oblivious summer vacations playing bridge and concealing from themselves the reality of the IRA ("the unpleasantness,") and concealing also from one another the longtime infidelity between two of them--Cynthia's husband Strafe with her good friend Milly. Not only has the group falsified this affair behind hypocritical chumminess, but each has further concealed from himself a set of private, territorial rages, tiny mirrors of international conflict.

One by one Trevor takes down the walls which shield them from truth and its reflections. Cynthia's lazy holiday is ruined when she witnesses a suicide in the surf just below their safe hotel. Worse, the victim confided in her first--a story of love reduced to rubble by a larger commitment to a violent Irish cause. Cynthia's shock makes her blurt out a further shock, that she has always known her friend and husband were liars, liars! And once Milly feels herself a true adulteress, beyond her own behavioral pale, she can admit wishing her friend Cynthia were dead. "Why couldn't it have been she who had . . . just walked into the sea?" At the end of one holiday and years of lies, the four fast friends confront not only death in the pleasant Irish countryside, but the murder in themselves.

The other 11 skillful stories clarify not only what Trevor protests against but which misbehaviors he prefers. He is steadily against the smug and self-righteous. In two stories characters commit, not first or third, but sixth-degree murder. In "The Blue Dress," a girl lightly touches the friend who is losing balance in a treetop. At "The Teddy-bears' Picnic," an old man falls against a stone one second before the companion steadies his arm. These near-murderers go beyond the pale but never care: the reader, or another character living through the story, knows and can do nothing.

"You couldn't trust those eyes," is the first line of "The Bedroom Eyes of Mrs. Vannsittart." Her reputation as the whorish wife of a henpecked cuckold is accepted by every minor character in this coarse, obvious story; only the reader is allowed past a final boundary to glimpse an even more bizarre love story hidden inside the first. "Mulvihill's Memorial" opens this way: "The man, naked himself, slowly removed the woman's clothes." But the minor misbehavior here is only a seduction on a clerk's secret pornographic film. On the story's third page that clerk dies riding down an elevator, and the other 18 pages will expose the worse secrets and the longer downward fall of all the polite, hypocritical people working in his business firm.

But Trevor, a fine writer in control of both his prose and his judgment, can sometimes invert his revelation and use one character's violence to produce another's peace of mind. The unseasonal warmth of "Autumn Sunshine" is saved for Canon Moran, a widower since spring and still mourning in the fall. "The trouble was that Frances hadn't yet become a ghost . . . the past refused to be past. Often he thought that her fingerprints were still in the rectory." In September, their daughter Deirdre visits, bringing a cockney named Harold who has adopted the Irish cause with all the fanaticism and wrath of the convert. He visits Kinsella's Barn, where in 1798 men and women were burned to death. His belated zeal on behalf of those victims and the distant Irish seems to the canon painfully like the zeal of the sergeant who ordered the burning in the first place. How can Deirdre love such a villain? The surprise at this story's core is the voice of his wife's good sense in the rector's head, separating as she always did in life what is abstract from real, legendary from immediate, in-perspective and out. "For the first time her death seemed far away, as her life did, too. In the rectory the visitors had blurred her fingerprints to nothing, and had made of her a ghost that could come back. The sunshine warmed him as he sat there, the garden was less melancholy than it had been."

In these splendid stories, such gentle revelations are rare. One can't help wondering what his London neighbors think of the talented, prolific, but always succinct William Trevor. He's very hard on Pharisees, whether from Oxford or the corner pub.