On Dec. 28, 1978, two American businessmen were arrested in Tehran and held in an Iranian jail; bail was set at the numbing figure of $12.75 million. Their names were Paul Chiapparone and Bill Gaylord. They were in Tehran as employes of Electronic Data Systems Corp., a Texas firm that had contracted with the shah's government to set up and operate a social security system. They were never told the specific charges for which they had been arrested, though the functionary in charge of the case implied that their incarceration was somehow connected to unsubstantiated bribery charges against their firm.

The arrests were met with immediate outrage inside the Dallas offices of EDS, in particular the office of its founder and chairman, H. Ross Perot, who a few years earlier had gained a measure of renown as a result of his efforts to arouse American sentiment on behalf of the prisoners of war held by North Vietnam. Perot had strings aplenty in Washington, and as soon as word came of his employes' detention he started pulling them. But his connections got him nowhere; the American government was reluctant to add fuel to the political fires then beginning to consume Iran, and the Iranian bureaucracy hadn't the slightest interest in accommodating American businessmen.

Thus it was that Perot, with legal solutions apparently closed to him, turned to an extralegal one: He enlisted the services of a Bull Simons, a 60-year-old retired Army specialist in daring rescue operations, and put him in command of EDS' own impromptu commando team. Its mission was to get Chiapparone and Gaylord out of Iran--a mission eerily prophetic of the one the Carter administration would undertake a year and a half later on behalf of the American hostages. But there was one important difference: The Simons mission was successful.

How it succeeded is described in "On Wings of Eagles," the first book-length work of nonfiction by Ken Follett, the author of several popular works of suspense fiction. He had the full cooperation of most of the Americans and a few of the Iranians involved in the drama, with the result that his interviews produced a massive amount of detail, much of which is interesting and some of which is repetitious.

It is a pity that his prose style does not do the story full justice; it is predictable and flat, and the reader whose cup of tea is one-sentence paragraphs will find that Follett has filled it to the brim. But he does know how to keep a story moving along, and in any event it would take a monumentally incompetent narrator to sap the suspense from this one.

"On Wings of Eagles" is a howdunit: Since we know from the outset that the two men were freed and returned safely to the United States, the mystery lies in how their rescue was accomplished. Follett begins with their interrogation and arbitrary arrest, which he considers "a barefaced act of blackmail," then moves quickly to the organization of Perot's private militia. Its seven members, apart from Bull Simons, were EDS employes who had varying degrees of military experience but were united by their friendship for their imprisoned compatriots and their loyalty to their boss. And all were what Perot called "eagles: highfliers, who used their initiative, got the job done, gave him results not excuses."

We're in the world of corporate macho here, and some readers are likely to find the incessant strutting monotonous and irritating; both charges certainly can be made against Perot, who, with his peculiar blend of militarism, messianism and religiosity, is a considerably less sympathetic character than the adoring Follett fancies him to be. But it remains that these men volunteered for an extraordinarily dangerous mission that held ample possibilities for imprisonment, injury or death, and that they carried it out with great ingenuity and courage.

How they did so will not be revealed here; suffice it to say that there are a number of agreeably interesting surprises and that several attractive heroes emerge, the most appealing of them being a young Iranian whose identity Follett feels obliged to disguise with a pseudonym. It is best to read the story for the suspense and not dwell overlong on the deeper implications, for domestic law and international relations, of what amounts to vigilante justice; Follett does a competent job of describing the means by which a desirable end was reached, but he does not trouble himself or the reader about the legality or propriety of those means.

That, no doubt, is because Follett seems to have become quite infatuated with the people who told him this dramatic story. The macho pose notwithstanding, it is easy to see why. More perhaps than anything else, "On Wings of Eagles" is a story about loyalty: of men to their fellows, of a company to its employes. Loyalty may be an outmoded virtue in these days of broken contracts and conflicts of interest, but as the men of EDS quite amply demonstrated, it does have its old-fashioned charms.