Reviewers like to call Ross Thomas' books "thrillers" or "suspense novels," but that's not really an accurate description. His books don't deal in thrills the way Ian Flemings' used to or keep the reader in breathless suspense the way Ken Follett's do. What Thomas does -- and he does it superbly -- is amuse.

His characters aren't frightening so much as funny. Take the Japanese terrorist in "The Mordida Man." Novelists like Trevanian and Eric Van Lustbader have taught us we'd better be wary of Japanese bent on violence, but how can you feel threatened by Ko, Thomas' character who thinks the way to taunt Americans is to scream "Babe Ruth eats s---!" Even when a small frisson of terror seems inevitable, Ross manages to avoid it. In "The Mordida Man," there is a scene in which the president of the United States is given proof that his brother, Bingo McKay, has been kidnapped. Now the evidence, in the best Getty tradition, is an ear, freshly chopped off the president's sibling. And that would be horrifying if the ear weren't neatly enclosed in a Guicci box, which is sealed with a freshly chewed stick of Dentyne (because, you see, the Libyan defense minister was all out of sealing wax).

Thomas' basic strategy -- and the one he uses in "The Mordida Man" -- is to give us a cast of mostly flat characters, grotesques, each of whom has one or two little quirks. Like Leland Timble, a Vesco-type expatriate who worries constantly about "contingencies" and who looks when he smiles like one of "those dumb faces that some people draw at the bottom of their letters." oOr like Alex Reese, the brilliant but slovenly CIA agent, who tells the agency's director (a man so fastidious he bolts down his office chairs so people don't sit too close), "You know what? I think I got crabs."

Even the protagonist is almost a caricature. Chubb Dundee ("Chubb" because his father was a locksmith; his older brother was named Yale) is also known as the Mordida Man because he is expert at using Smordida (bribery in Spanish slang) to rescue people who have got themselves jailed, kidnapped or otherwise inconvenienced. Dundee was once an ambassador to the United Nations, and before that a congressman, but when his wife Nan called him a crypto-fascist and took off with the Weathermen, his constituents turned him out. (Which does, I think, strike a bit of a wrong note. While I've seen many an election salvaged by a savvy wife, I've never seen even the most bizarre spousal eccentricities lose one.)

At any rate, Dundee is called in to help the president because Felix, a freedom fighter under Libyan protection, is kidnapped, and the Libyans, thinking the CIA has done it, snatch the president's brother. But it wasn't the CIA who took Felix, it was Leland Timble, except he doesn't have Felix anymore, though he is in possession of the freedom fighter's forefingers . . . and that brings us to about page three.

I exaggerate, of course, but the book's twists and turns comes almost that fast. Another thing reviewers like to say about Thomas is that they read his last book in a single sitting, in "one delicious gulp," I believe is the expression. I have almost concluded that it's a matter of survival to do so. Thomas' plots are so treacherously complex that once you get out and forget where the whirlpools are, you're likely to drown should you try to go in again.

The reader Thomas appeals to is the one who likes crossword and other puzzles, the one who delights in the neat fitting together of every last part. It does indeed bring a moment of satisfaction when the dope-crazed American appears on page 183 and you remember someone mentioned such a character in passing 80 pages earlier. Of course, a writer who deals in such subtleties will be held accountable to a high set of standards. Readers who can remember 80 pages are going to feel cheated at the end of the book when Bingo McKay marries his assistant, Dr. Eleanor Rhodes. Back at the beginning it was carefully explained that Bingo shouldn't marry Eleanor because he suspected she was bedding down with the president. And here he is marrying her, and her sleeping habits never have been cleared up.

But that is niggling at what is extremely skillful entertainment.