MOVIE REVIEW : The Firm of Julia, Denzel, Grisham & Pakula : ‘The Pelican Brief’ is based on a hot novel, has bankable stars and a director noted for his work with thrillers. The case has been made and the verdict is . . .

If “The Pelican Brief” (citywide) had any more going for it, it would be against the law. So it is a surprise to say that the biggest mystery this legal thriller presents is how a film based on a novel by John Grisham, starring the bankable duo of Julia Roberts and Denzel Washington and written and directed by veteran Alan J. Pakula can end up more of a fizzle than an explosion.

“The Pelican Brief” does have its moments, sporadically involving episodes when it looks like things are finally going to ignite. But that combustion point is never quite reached, and despite occasional bursts of action, this doesn’t manage to be more than a reasonable facsimile of a thriller, acceptable in a pinch but nothing to get very excited about.

This year has already seen a much more successful version of an earlier Grisham novel, the Sydney Pollack-directed, Tom Cruise-starring “The Firm.” Aside from a penchant for all-star casts, both movies benefit from one of Grisham’s enjoyably harum-scarum plots, outlandish yet just plausible enough to be diverting.

The story this time around centers on the Supreme Court, whose oldest justice, the liberal Abraham Rosenberg (a clever cameo by Hume Cronyn) is the target of anger from all across the political spectrum. So while no one is surprised when he comes to a sudden end, the fact that another justice of a different political stripe is simultaneously murdered is the cause of considerable speculation.

Among the interested parties is humble but smart Tulane University law student Darby Shaw (Roberts). Working on the premise that it might be greed, not ideology, that led to the deaths, she puts together a paper on the possible causes, which, for reasons that will eventually become clear, she calls “The Pelican Brief.”

Shaw’s professor/boyfriend Tom Callahan (Sam Shepard) thinks enough of Darby’s brief to pass it on to old pal Gavin Verheek (John Heard), who just happens to be a top lawyer for the FBI. In this time of conspiracy theories and contagious paranoia, it will unnerve no one to find out that once the government, up to and including the President (Robert Culp) and his ominous chief of staff (Tony Goldwyn), get involved, Darby’s life is at risk. Finally, the only person she can trust is Gray Grantham (Washington), the best reporter the nation’s capital can call its own.

Set up this way, “The Pelican Brief” probably doesn’t sound half bad. But a simple description leaves out several factors that work to the film’s detriment, starting with the nature of its view of official Washington.

For once the word gets out on Darby’s brief, entities almost without number get involved, ranging from all the President’s men to the FBI, the CIA and several clandestine intelligence organizations.

So while everyone is looking for Darby, it is far from clear who anyone is or what their intentions are at any given time. In fact spies are spying on spies to such a baffling extent you’ll want to construct a chart to figure out what’s going on, and a darkened theater is not the best place to make one.

Not helping things either is that, unlike “The Firm,” “The Pelican Brief” doesn’t benefit from the strength of its supporting performers. With the exception of John Lithgow’s steely editor, almost none of the peripheral players and especially none of the innumerable government men make much of an impression. Roberts and Washington do what is expected of them quite nicely and manage a pleasant on-screen rapport, but no one is giving them much assistance.

The person who should be helping most, director-screenwriter-co-producer Pakula, who has thrillers ranging from “Klute” and “The Parallax View” to the more recent “Presumed Innocent” and “Consenting Adults” behind him, is a considerable letdown on this one.

Aside from not being able to keep the plot from becoming periodically murky, Pakula sets a leisurely, almost phlegmatic pace for this film. The material is treated with more reverence than energy, and in a year when splendid thrillers like “The Fugitive” and “In the Line of Fire” can be held up as examples, that is simply not good enough.

‘The Pelican Brief’

Julia Roberts Darby Shaw

Denzel Washington Gray Grantham

Sam Shepard Thomas Callahan

John Heard Gavin Verheek

Tony Goldwyn Fletcher Coal

James B. Sikking Denton Voyles

Released by Warner Bros. Director Alan J. Pakula. Producers Alan J. Pakula, Pieter Jan Brugge. Screenplay Alan J. Pakula, based on the book by John Grisham. Cinematographer Stephen Goldblatt. Editors Tom Rolf, Trudy Ship. Costumes Albert Wolsky. Music James Horner. Production design Philip Rosenberg. Art director Robert Guerra. Set decorators Lisa Fischer, Rick Simpson. Running time: 2 hours, 21 minutes.

MPAA rating: PG-13 for “momentary language and some violence.” Times guidelines: There are several murders in the film and a certain amount of tension.