Sympathy Found in Time : REPLAY <i> by Ken Grimwood (Berkley: $3.95, paperback; 313 pp.) </i> : LINCOLN’S DREAMS <i> by Connie Willis (Bantam Spectra Books: $15.95; 212 pp.) </i> : THE FALLING WOMAN <i> by Pat Murphy (TOR Books: $3.95, paperback; 287 pp.) </i>

Of the four physical dimensions, time is unique. We move pretty much at will in the three spatial directions, but time binds us in the ever transient “now,” sweeping each of us into an unknown future, leaving our past behind. The only exception is subjectivity--how we use our minds to perceive this passage. In memory and in imagination, we all have our time machines.

From the blurry recollections of magic realism to the explicit thought experiments of science fiction, speculative literature has long pondered the human obsession with time. Between the art-as-detail of a Gabriel Garcia Marquez or a Marcel Proust and the scientific time-travel explorations of an H. G. Wells or a Gregory Benford, there lies a broad range of works dealing with how this obsession affects people, personally.

Three such novels have appeared recently. Each is set in recognizable locales, with none of the technogimmickry that drives some readers away from more extravagant varieties of science fiction. Each shows touchingly how a person might enter into an unusual relationship with time.

Connie Willis’ first novel, “Lincoln’s Dreams,” fulfills all the expectations of those who have admired her award-winning short fiction. It is the story of Jeff Johnston, a young researcher for a historical novelist, who meets Annie, a woman suffering from vivid, recurring nightmares set amid the horrible battles of the Civil War. The dreams depict things Annie cannot ever have seen or read. Jeff soon realizes that they can only have been dreamt by one person, a man already one century dead--Robert E. Lee.

There is some action as Jeff helps Annie escape from an obsessed psychiatrist, whose misdiagnosis has potentially fatal consequences. But for the most part, “Lincoln’s Dreams” is taken up with the moral and mental dilemmas of two people caught in a gentle, sad mystery. Are these the real dreams of Robert E. Lee, that kindly, guilt-ridden man, whose brilliance prolonged a war and sent thousands to their deaths? Or is something else happening altogether in “Lincoln’s Dreams”?

Whether writing drama or witty humor or, in this case, a poignant examination of duty, Willis conveys through her characters a sense of transcendent pity that few modern authors ever attempt.

“The Falling Woman,” by Pat Murphy, takes a similar initial concept in radically different directions. Elizabeth Butler is an archeologist excavating a long-dead Mayan city, when the daughter she has not seen in 20 years suddenly appears at the dig, suitcase in hand, seeking refuge from the modern quagmires of urban life. Reconciliation between strong-willed women after two decades apart would be difficult enough but the jungle-covered ruins of the Yucatan now offer both women another, possibly deadly challenge--one presented by the shadows of the past.

Elizabeth, it seems, walks both in the present and among the faint images of older times--images only she can see. On a busy street corner, for instance, she might watch, walking past, a band of neolithic hunters who had used that same site centuries or millennia ago. This parallel vision has made her renowned among archeologists for her “hunches.” It has also convinced Elizabeth that she is not, in a basic sense, sane.

Murphy’s novel contains more of the standard elements of contemporary fiction--obligatory doses of sex and threat and violence--than Willis’, and yet the similarities make for an interesting comparison.

Our third dramatic exploration of time is more explicit, more in keeping with the conventions of science fiction, for it is about “actual” time-travel of a sort. And yet, where the basic gimmick in Ken Grimwood’s “Replay” might have been exploited trivially by someone else, in this case the author achieved something truly remarkable.

Simply put, Jeff Winston, a middle-aged radio news director, drops dead of a heart attack on April 18, 1988. He wakes up then . . . amazed to find himself in his old college dormitory room. He is 18 again. It is 1962. And he “remembers” every major event destined to happen over the next 26 years.

The first section of “Replay” is what one might normally expect, given this premise. What would you or I do, under such circumstances? Winston uses his knowledge to get rich, to become a billionaire, to try to avert some of the worst calamities of the ‘60s and ‘70s, with mixed success. Then, a happy, contented, powerful man, he reaches Oct. 18, 1988 the second time around, and promptly drops dead again . . . to awaken once more at Emory University, age 18, remembering.

“Replay” features one of the more thorough explorations of a theme one might ever hope to find. Over and over, Jeff Winston is forced futilely to relive those 26 years. Each time around he tries some new approach, some different way to find meaning in it all. Then, in the midst of yet another cycle, he encounters clues that someone else may be replaying, also.

By necessity, Grimwood’s speculations are on a grander scale than Murphy’s or Willis’. His theme will have the reader daydreaming--”What would I do?”--and coming to fascinating conclusions. If the end of the book may leave some feeling suspended, other readers will carry on thinking for days, trying in their own ways to solve the riddles Grimwood poses.

In its tone and deeper messages, “Replay” addresses many of the same issues Murphy does in “The Falling Woman” and Willis in “Lincoln’s Dreams.” All three writers share the rare authorial trait of clearly liking people. All three offer characters rich in insight and sympathy. All three challenge us to take fresh views of that inexorable force, time.