By Eric Bercovici

Birch Lane Press. 249 pp. $17.95

Eric Bercovici's comical new mystery novel comes along at a good time. With van Goghs going for $82 million, a lot more people than usual are pondering the connection between authenticity and value, wondering whether Keats's equation of truth and beauty really holds up in the mathematics of today's art market.

Amicus Maltese, the expert in "provenance" who is Bercovici's detective hero, has always resisted the connection: "Personally, some of my favorites were fakes. Giovanni Bastianini's bust of Savonarola, attributed briefly to both Michelangelo and Luca della Robbia ... is still my favorite terra cotta regardless of the fact that it was created only slightly more than a hundred years ago." But authentication is Maltese's business, one in which a bit of paranoia is, by his own admission, an occupational strength.

This time he has been hired to determine the true origins not of a painting or sculpture, but of what may or may not be the manuscript of a novel by Oliver Godolphin, a world-famous writer who died seven years before in a helicopter crash. Godolphin's own origins are rather mysterious: Reference works make it seem that he "simply appeared from nowhere in 1955 in Marseille after having served ('avec honneur et fide'lite'') in the French Foreign Legion."

In the course of his efforts to find out who wrote "Sakura" and why it's only now surfaced, Maltese must deal with Swiss bankers, British publishers and a Hollywood producer, making quick, chic transits between London and Geneva, Nice and Rome, Marbella and Salzburg. Along the way he's drawn into renewed dealings with his ex-wife, Fiona, with whom he is still desperately in love, despite her having left him for two subsequent husbands and, currently, the attentions of rock star Roddy Startle. More sympathetic and no less beautiful is Oliver Godolphin's daughter, Alexis, who is unconvinced of the genuineness of "Sakura." For the purposes of his investigation, however, the most important woman for Maltese to find is "L.W.," the recipient of the novel's dedication.

Maltese's method of establishing literary provenance will strike many readers as decidedly far-fetched, not to mention expensive, and some of his unfamiliarity with the field is reflected in Bercovici's own failure to establish very clearly what sort of writer Oliver Godolphin was. We're told he won a Nobel Prize, but his books are available on airport racks.

"Tread Lightly" can be stylish fun, especially when Fiona reduces Maltese to Perelmanic helplessness ("My mind was on fire, my heart wrapped in briars"), but one truly mysterious feature of Bercovici's book involves not its plot but its occasional lapses from polished wit into lewdness. The customary speech of Fiona's business partner, Sally Morgan, is too crude to be true, or to quote, and the same is true for the Hollywood producer, Danny Speers. The novel seems to suffer from a kind of Tourette syndrome, a compulsion to talk dirty in bursts, whether it's Sally or Danny speaking, or Maltese himself discoursing upon the inconvenience presented by the behavior of the remarkable part of his body that he calls, variously, a monster, crowbar and Godzilla.

All this is not just off-putting, but a shame as well, since Maltese is an interesting sort of detective -- someone whose jet-setty competence at tracing forgery through the world's glamour capitals is counterbalanced by a woeful sense of inadequacy and a comical susceptibility to emotion: He weeps, he faints, he slumps exhausted in his chair. Part of his psychological trouble comes from having a father whose business is not fact but fake, a dealer in frauds who "could sell a Frans Hals with the paint still wet." A good deal of this is choppily presented and under-dramatized (if a first-person narrator has to ask "Was I having an identity crisis?" he can't afford one), but none of it is such a bad idea.

Bercovici, who in addition to film and television scripts has written the mystery "So Little Cause for Caroline" (winner of an Edgar Allan Poe award), has a terrible time winding up this book, and he holds on to his plot and characters for about 50 pages too many, apparently unsure whether to go, in the end, for farce or feeling. Still, don't be put off by the Jackie Collins quotation on the jacket; the book isn't nearly as bad as her endorsement would normally indicate. More to the point is the epigraph, taken from John McEnroe: "Things are never as good or as bad as they seem." It is the perfect caveat emptor for a very uneven novel.

The reviewer's most recent book is "Stolen Words: Forays Into the Origins and Ravages of Plagiarism."