Never have the gossip-friendly realms of money, art, celebrity, sex and scandal come together with such earthshaking force as they did in the summer of 1959, aboard a richly appointed yacht, the Christina, as it plied the waters of the Aegean Sea. The infamous three-week cruise-which drove a tempestuous opera diva into the arms of a billionaire shipping tycoon while their respective spouses looked on, awestruck-is at the molten core of Greek Fire: The Story of Maria Callas and Aristotle Onassis (Knopf), Nicholas Gage's meticulously researched and absorbing chronicle of one of the 20th century's most spectacular love affairs. It has often been remarked that the Callas-Onassis liaison resembled a grand opera of the sort that La Divina, as she was known, sang with such furious passion. A more accurate comparison would be to three or four operas, plus a drawing-room farce and a Sophoclean tragedy, all woven together with strands of Hellenic myth. To begin with, of course, there is the unhappy fairy tale of Callas' career. She turned herself into the most celebrated opera star in history, in the process utterly destroying the precious instrument that made her a legend. At the height of her powers, she largely abandoned music and devoted herself to Onassis, only to be tossed aside when Jacqueline Kennedy caught his eye, spending her final days secluded in her Paris apartment, popping sleeping pills and watching TV Westerns with her poodles. To this melancholy arc, Gage adds some startling details, such as the bizarre tale behind the diva's dramatic weight loss early in her career, a transformation brought about when, sources say, she intentionally ingested a tapeworm. Following his ill-considered marriage to Jackie, Onassis too would experience more than his share of calamity (of course, he also had more than his share of everything else). He no doubt imagined that he'd offended the gods somehow as, in quick succession, his various business endeavors began to founder; his beloved son, Alexander, was killed in a plane crash: his ex-wife, Tina, married his detested rival, Stavros Niarchos, and died soon after, and his own health began to falter. Onassis' employees attributed all these setbacks to the "Jackie jinx." Meanwhile, his frantic attempts to win Maria back, whistling "the sailor's whistle" outside her Paris apartment mere weeks after his remarriage, came to naught. This astonishing jet-set saga has been breathlessly chronicled from the moment it began, but Gage, a former investigative reporter for the New York Times, is intent on stripping away the tale's patina of fantasy (much of it applied by Onassis and Callas themselves), and he approaches the task with a doggedness Kenneth Starr surely would admire. He studies the layout of the ship, for instance, to determine the most likely spot for the couple's assignations. "They probably would have chosen the largest launch," he decides, "on the port side of the boat deck, just forward of the plane." He pores over paparazzi shots for clues. And he obtains interviews with a host of eyewitnesses who have steadfastly refused to speak before, among them Callas' devoted maid. She confirms the book's most explosive revelation, that Maria gave birth to Ari's son, Omero, who died the day he was born. (With characteristic zeal, Gage also uncovers not only the death certificate but a photograph of the child's lifeless body.) The addition of this tiny but pivotal character to the drama lends further resonance, as if any were needed, to an altogether grievous love story.