It is doubtless a sign of the times that a genre writer, such as Donald E. Westlake, can today command a sum of $45 for a signed, numbered, slipcased edition. Westlake is known for his caper novels, many of them written under pseudonymns, often concerning seemingly amoral characters who turn out to be all right in the end. This new book follows that pattern in lackadaisical, good-natured fashion. It is an inoffensive romp that offers a few insights about Central American politics while it wistfully has everything come up roses, except in the case of one mean-spirited minor bureaucrat who deserves punishment if anyone in the story does.

The bureaucrat in question is employed by the government of Belize, a tiny English-speaking nation nestled between Guatemala, Mexico and the Caribbean Sea -- a savory setting for any caper yarn, what with the inevitable echoes of privateers and adventure on the high seas.

In this case, the privateer is one Kirby Galway, a bush pilot in the habit of smuggling marijuana out of Belize, a business practice not deemed particularly offensive by the local authorities. Galway, a dashing ne'er-do-well if there ever was one, is far more likely to get in trouble for smuggling out Mayan artifacts in bales of fine ganja, a practice that is frowned upon by everyone but two antique dealers from New York, as well as the curator of a midwestern museum.

These three are the intended victims of the scam at the heart of "High Adventure." To complicate matters, Westlake tosses in a beautiful, high-spirited archeology student from Illinois and a Belizean real estate agent who just happens to be deputy director of land allocation to boot. There is also a complement of Indians, who are all essentially benign and allied with Galway in his comically mercenary schemes. Indeed, with the exception of a Nicaraguan colonel -- a rarely seen character -- there is very little outright nastiness on display, just a great deal of bungling and mistaken identity, the stuff of high comedy more than high adventure.

Nevertheless, Westlake does provide us with enough thrills along the way to justify his punning title. We are also permitted to swallow a sugar-coated history and cultural anthropology lesson about Belize, a nation with which most Americans are probably not familiar. Knowing comments on the human condition surface amusingly from time to time; a particularly fine example is a dinner sequence that Galway has managed so that his various intended marks won't recognize each other, even though they are all eating at the same restaurant. Galway gets away with it in Belize, but the marks stumble across one another in New York anyway, an irony that somehow bears the stamp of authenticity.

As does Westlake's treatment of Central American culture, past and present. He lectures us entertainingly and briefly on "Popul Vuh," the creation myth of the ancient Mayans, and introduces us to an evil god named Zotzilaha Chimalman, or Zotz for short. Even while he's kidding around, Westlake treats the people and place with respect. Nor does he present us with the cliche' of natives inevitably corrupted by contact with 20th-century technology. Luz and Tommy, two young Indian males who have lived in the United States, are wise to the ways of the world even as they are at home in the Belizean jungle. In the end they have chosen the world of their childhood rather than the big cities of the United States, but they have not suffered from leaving the jungle for a few years. They refer to Galway as Kimosabe throughout the novel, as they help him first create and then tear down a Mayan temple on the soggy parcel of land sold to him by Innocent St. Michael, the sly real estate dealer and bureaucrat who conducts a love affair with Valerie Greene, the American student, before she is lost in the jungle.

Much of the plot revolves around her adventures, and Westlake comes up with quite a few surprises for Valerie and his readers before the climax, a pyrotechnic display mixing modern technology with ancient superstition. It's all neatly worked out in the finest tradition of the caper novel, as one might expect from a veteran of more than 20 years at this sort of thing.

It is this wealth of experience that has sharpened Westlake's skills over the years. He is an invisible author most of the time, a craftsman whose easily drawn characters speak for him. His carefully conceived plots seem to grow naturally, but are never simple-minded. While he appears to eschew the profound, he works with an elegance that might be the envy of many an ambitious writer. These are the gifts that have served him well in his lengthy career, entitling him in the long term to such auctorial benefits as the aforementioned $45 signed, numbered, slipcased edition. More than one highly touted literary discovery has fallen by the wayside while Donald E. Westlake has endured and prospered.