Here is a golden opportunity--golden for someone, at any rate. For merely three times the price of a first-run ticket to "Raiders of the Lost Ark" (which may or may not have been worth it), we are offered approximately one-third as much action, suspense, exotic scenery and romantic interest. And instead of technically expert cinematography, the medium is prose that ranges from mediocre to bad.

"Raiders of the Lost Ark" may not have been much, once you got past the gee-whiz visual effects, but at least it had the grace to make fun of itself occasionally. Like that problematic film epic, "River of Death" features Nazis, hidden treasure, travel to exotic, dangerous places and a hero who is so flawlessly capable as to defy all credibility. It also offers spectacular threats and a fast-moving series of catastrophes so vividly visual that you can almost feel the cameras moving in for a closeup:

See a lost city hidden for centuries in the rain forests of Brazil! Ride with an intrepid party of explorers down the treacherous Rio da Morte, facing threats from cannibals, spiders, the dread anaconda and (what could we do without them?) the ever-present, ever-hungry piranha! Share the jolting suspense of a helicopter crash on an island teeming with alligators! Ride a hydrofoil down the rapids of the River of Death, over a waterfall and down, down, down into the swirling waters below! Share the agony of prisoners in a dungeon, knowing that they must die at dawn! Try to guess who is who on this incredible journey, and what they are seeking in this treacherous jungle!

You will have to do it, of course, without the benefits of a big screen, vivid color, brilliant special effects and stereophonic Dolby sound--at least for the moment. Eventually, perhaps, someone will make the movie that is obviously the ultimate objective of this latest novel by the author of "The Guns of Navarone," "Ice Station Zebra," " Where Eagles Dare" and more than a dozen other thrillers. Until then, you are advised to wait. Although it has some good moments (mostly near the beginning), this material will not be fit for human consumption until it has been processed onto film. Because what Alistair MacLean has written is not a novel but a scenario, leaving to some future directors, actors and cameramen the job of making the material real, vital and interesting.

He has given them a good many interesting technical challenges (see the partial list above!), but he has also imposed on them some serious problems. There is, for instance, the curious fact that everyone of any real importance in the book is traveling under a false or secret identity. One of these can make a fine coup de the'a tre if the truth is revealed dramatically at the proper moment. But a half-dozen of them, piled one on top of another, require of the reader an effort something like reading a phone directory in an exotic alphabet.

His style doesn't help much, either. It often reads like a translation from an obscure and convoluted foreign language. Consider, for example, this passage, where a group of people have just seen the first aerial photos of an ancient lost city hidden away in the jungle:

"They knew they had seen something that no white man, with the exception of John Hamilton and his helicopter pilot, had ever seen before, something, perhaps, that no one had ever seen for generations, maybe even for centuries. They were hard people, tough people, cynical people, people who counted value only in the terms of cost, people conditioned to disbelieve, almost automatically, the evidence of their own eyes. But there is yet to be born a man or woman the atavistic depths of whose soul cannot be touched by that one questing finger that will not be denied, that primitive ancestral awe inseparable from watching the veil of unsuspected history being swept aside."

It is practically an anthology of infelicities: the sweeping, universal statement ("no white man . . .") with the quick demurrer (well, not very many); the curious air of fuzzy impressiveness hovering between "ever," "perhaps" and "maybe," the slight upward lurch toward infinity in the step from "generations" to "centuries"; the brass-tacks description of a room full of tough guys in that tortuous sentence where "people" occurs five times in 30 words, even bumping into itself once with only a comma as a buffer. And finally, there is the superbly muddled statement about the questing finger in the atavistic depths and the veil of unsuspected history, where the thing seen (the veil) seems to be confused with the thing being hidden behind it (history), and the thing revealed (history) becomes syntactically a part of the thing (the veil of unsuspected history) being swept aside.

In our degenerate age, such a Rube Goldberg structure of words can sometimes pass (among the inattentive) for "fine writing," perhaps because it uses such exotic structures as subordinate clauses. It is not; it is the writing of a man in a hurry to get his day's quota of words on the page so that he can go off to his golf, or whatever he considers really important. It is the work of a man who knows that the literary style does not really matter because his work's ultimate destination is a nonliterary form with lights, cameras and action. And it is all the more pitiful because it comes from a man who has sometimes produced readable if not distinguished work.