In an age when some people call Madame Cleo and others apparently believe that John Edwards really crosses over, there may be an audience for the pretentious hooey that Tom Shadyac is hawking in “Dragonfly.” Coming as it does from the director who gave us “Patch Adams,” it’s not surprising that the picture is mawkish, manipulative and phonily uplifting. In this case, however, it’s also a dumb attempt at a thriller, utilizing the same kind of cheap shocks that Robert Zemeckis deployed in “What Lies Beneath.” But at least Zemeckis intended his movie to be a lark; one has the suspicion that Shadyac intends this howler to be taken seriously.

The narrative centers on Dr. Joe Darrow, a supposedly brilliant emergency room physician at a Chicago hospital, whose equally brilliant wife Dr. Emily Darrow (Susanna Thompson), a specialist in pediatric oncology, is tragically killed in an accident while serving with the Red Cross in South America–though her body is never found. The grief-stricken widower begins to have experiences suggesting that his wife is trying to contact him from beyond. Images of the dragonfly–her talisman of choice, it appears–keep appearing to him in spooky ways (apparently all the moths were already engaged with Richard Gere and his “Prophecies”), and kids from her ward who’ve had near-death experiences tell him she’s trying to reach him with some message of great, but unexplained urgency. Joe’s search for the truth makes those around him–his colleagues and down-to-earth next-door neighbor Mrs. Belmont (Kathy Bates) fear for his sanity. Nonetheless he persists, even going so far as to contact a diminutive nun (Linda Hunt) who’d been doing research on near-death experiences with Emily’s patients, until scandal forced her to stop. And eventually he tracks down the solution to all the weird goings-on. The distributor has asked reviewers not to reveal the surprises of the last reel, and that’s a fair request. But it must be said that even a dim bulb of a viewer should have little trouble foretelling where and how this journey will end–especially if he pays attention to the periodic flashback sequences to Joe and Emily’s happy days together.

All of this is the purest hokum, made almost unendurable by the solemn, ponderous pace that Shadyac adopts (lots of shots of an anguished Costner staring blankly into space, and periodically going into a frenzy), and his habit of squeezing every drop of emotion he can out of each scene. While the direction accentuates the weaknesses, however, it’s the script (by veteran David Seltzer and neophytes Brandon Camp and Mike Thompson) that provides them. Most of Seltzer’s earlier screenplays have been pretty bad (“The Omen” and “Lucas” being the primary exceptions, but they can hardly compensate for lulus like “The Other Side of the Mountain,” “Six Weeks,” “Table for Five,” “Prophecy,” “Bird on a Wire,” “Punchline” and “Shining Through”); this is one of the worst (though the Camp-Thompson duo must share blame). Not only does it employ every mindless device known to cinema to generate shocks (figures appearing suddenly from the dark or abruptly crashing into the frame are obvious examples), but it doesn’t play fair even within the compass of its own premises. Much is made, at first, of Emily contacting Joe through the near-death experiences of her young patients–a conceit which allows Shadyac to give us a parade of youngsters who are second literary cousins to Haley Joel Osment’s Cole Sear- -or, later, of a brain-dead organ donor; but elsewhere Emily seems to be able to approach Joe directly, through insistent insects and maddened birds or by merely rearranging furniture and bric-a-brac, poltergeist-style. The bewildering variety of means open to Emily has no other point, it seems, than allowing the audience to be jolted as often and variously as possible. When the script turns from shocks to tears, moreover, it’s absolutely shameless, serving up a denouement that’s not only ridiculous but almost risibly mawkish.

In fairness, it must be admitted that “Dragonfly” does play to Kevin Costner’s only remaining strengths as an actor–his ability to look perpetually stolid and uncomprehending. Otherwise the picture wastes the thespian talents of people like Hunt, Ron Rifkin, Joe Morton, Jay Thomas and Matt Craven. Thompson is agreeable as Joe’s wife but little more. Of the major players only Bates emerges unscathed, blustering through her part with gruff matter-of-factness, though Jacob Smith, looking remarkably like a young Elijah Wood, has a nice cameo as one of the ill children who act as Emily’s messengers. Technically the picture is slickly made, with cinematography by Dean Semler that creates a suitably gloomy atmosphere of vague dread. It doesn’t make good use of the Chicago locale, though–suggesting that most of it probably wasn’t shot there–and surely Don Zimmerman’s editing could have punched things up more.

At one point in “Dragonfly,” Hunt’s Sister Madeleine portentously informs Joe of the “murky depths” that make up the experience of dying. It’s a phrase that half-applies to the movie: the adjective is utterly appropriate, but the noun is not. Despite its subject, this is a very shallow and insubstantial picture. Rod Serling would have polished off so feeble a story in thirty minutes in the old days, and he still would probably have been embarrassed by the result.