The hero and narrator of this whodunit is a hard-boiled academic, Thomas Theron. He teaches American Civilization at Wesley, which we are encouraged to think of as Harvard (where Robert Reeves himself once taught).

But Theron doesn't exactly brag about this. As the corpse he discovers is carted away, Theron only reluctantly gives the information to police. He teaches, he says, at "an institution of higher learning." When the cop responds, "Higher than what?" Theron offers, "Higher than O. Henry . . . but lower than Gravity's Rainbow."

The line is a perfect example of Thomas Theron's brand of humor. Laugh at it and be assured that you'll keep on laughing throughout. If there's any one thing that Theron does consistently, it's keep the snappy patter coming.

Take, for example, his view of the town: "Ah Cambridge. I lived in a community of militant nonsmokers, militant nonsexists, militant non-meat-eaters, militant no-nukers. I found peculiar comfort in the knowledge that I could, on short notice, offend the entire population by sitting over the remains of a rare T-bone steak, smoking Camels, telling dirty jokes, occasionally interjecting belligerent asides about the Russian threat." But Theron doesn't let himself off the hook here. He concludes, "My pleasure in this was only slightly tainted by the deeper knowledge that I, with my own militant cynicism, was every bit as predictable as they."

Is he really? No way. One look at the hungover Theron bluffing his way through a lecture on the 19th-century novel will tell you that. And consider, too, Theron's response when his digs are ransacked: "One good thing . . . About forty yellow-and-black pamphlets comprised part of the clutter on my apartment floor. For weeks I'd been wondering in which box I had stored my Cliff's Notes."

Of course we knew that he wasn't your average college prof from the book's opening sentence: "I left the old man lying there, curled around a commode in the men's room at Suffolk Downs . . . "

Theron credits his trips to the track with pulling him "out of my own deadening academic routine, out of the collegiate calm where no risks were taken, where tenured futures were monotonously secure . . ." There's one thing wrong with this observation: he doesn't have tenure.

He's up for it, though, and the issue of his tenure manages to figure into a plot that involves him with not just touts and tipsters, but prostitutes, a cult leader, a wonderfully cultivated mobster and a colleague whose eccentricities are bowdlerized when given in summary: "his apparent obsession with a young stripper, his seeming preoccupation with suicide, his alcoholism, his tragic shortcomings in personal hygiene." Reeves is able to keep the whole thing, including Theron's coercion into sleuthing, moving swiftly, believably and hilariously to its conclusion.

But there's more to the book than this. Thomas Theron's jokes are persiflage and he knows it, admits it. His gambling derives from more than a simple hope to get rich quick (though he tells us, after he wins $31,750, "Half again what I earned in a year. Wesley College, according to its own smug formula, paid part in money and part in prestige"). Consider, "Today was among the five or six times in the past three years that I hadn't found a way to lose. I had been winning, drinking, betting recklessly, and still winning. But there was still a race left; failing that, there was still tomorrow."

So Theron hooks us in another way, a serious way. He comes on with a kind of fail-safe allure, that of the grown-up bad boy. Because he can tell us about his dark side, because he sees it so clearly and articulates it so well, we believe his problems solvable. Theron can be redeemed. We read on in part to see him redeemed.

But the can-this-man-be-saved motif also provides a substantial subplot, involving as it does Theron's relationship with his ex-wife, Beth. Once a student, now (and no wonder) a psychotherapist, Beth is still drawn to him, but warily, no longer sure that his occasional calls for help aren't, in the end, just his gimmick, just his way of drawing her, as he draws the reader in. Nothing solemn here, though; just an anchor to keep the book from sliding into slapstick.

When we leave Theron this time -- for the jacket promises that "Doubting Thomas" is the first in a series -- he's in fair shape. He's a long way from yearning as he did at the book's start, to be "just another schmuck fingering a Racing Form." Or, wait a minute, is he? We can't wait for Robert Reeves' next entry, so we can check up on his hero and see.