James Grady is primarily known not for his novel "Six Days of the Condor" but for the remarkable 1975 film derived from it, "Three Days of the Condor," which may have lost half its supply of days in the transition but picked up the extraordinary talents of director Sydney Pollack, as well as actors Robert Redford, Max von Sydow, Faye Dunaway and Cliff Robertson in a particularly chilling performance. As the years have passed the film has become a genre classic while the novel is now pretty much forgotten. Of such ironies is a novelist's life composed, although the process is more frequently exemplified by a novel's reputation sullied by an unhappy film interpretation.

Now Grady is back in the chase with his fifth novel, "Hard Bargains," the second to feature Washington detective John Rankin, who shares some of Grady's past, including a '60s sensibility stranded in an increasingly '80s world and a period spent as an investigator for a big-time muckraking columnist, in the author's case, Jack Anderson. He brings both his sensibilities and his experience of Washington's ins and outs to the table in "Hard Bargains," and when he hews to those lines his work is confident, complex, realistic and unfailingly interesting.

When he ventures into the more treacherous waters of characterization -- particularly in the matter of the central woman, an enigma trapped in a puzzle surrounded by a riddle -- we long for him to hasten back to his plot, his broadly effective villains (watch out for the fellow who always says "old chap" -- such a clod must be up to no good), cops, political action committees, shady fixers and the general Washington milieu with which he is so familiar.

While Rankin is slow to come alive on the page, many of the crucial secondary characters come right at you as the story snakes its way backward through several years toward the mystery surrounding the murder of a wonderfully vile creep called Parvis Naderi and the interest a woman -- who turns out to have more than one identity -- has in how the long-dead investigation now stands. Calling herself Cora, she hires Rankin to check it out; but when there seems to be some life in the old case yet, she turns out to be Barbara, the wife of a prime mover-and-shaker with an estate and horses in the Maryland hunt country. Rankin, susceptible in the way of private eyes, is hooked: both on the woman and on discovering why she might be so curious about the hit made on Parvis.

Where the search takes him is what makes "Hard Bargains" more than routinely diverting. Grady may not be at his best writing about a femme fatale, but he creates a convincing cop named Nick Sherman, who would make a fine protagonist, full of life and sorrow and cynicism and weary decency. The same can be said of Sam Murray, a grizzled old knight on a creaky hobby horse, trying to organize the independent truckers in opposition to the Teamsters; and an investigative reporter who opens up a Pandora's box for Rankin while simultaneously wondering where the hordes of single women Washington is said to possess may actually be; and even the bit part of a former Iranian general now driving a cab at Dulles who takes the time to wish Rankin a happy Fourth of July.

Through it all, Rankin tracks the slippery, infected trail left by Naderi right back to where you always knew it would lead; and in the end, of course, such stories never have happy endings. In a lovely concluding irony, Rankin realizes that they all got what they wanted and nothing did them any good. But for the reader, Grady has provided a tour of the power underbelly that has the look and feel of the real thing. There are even moments reminiscent of the great model for all such novels -- based on the idea of exhuming the life of a scoundrel -- Eric Ambler's "A Coffin for Dimitrios." To put one in mind of Ambler, however fleetingly, is no small accomplishment.