THINK OF $25 MILLION. Then look back over the last 14 years. Imagine how those years could have been -- spending that $25 million. An exotic fantasy, but one that Barbara Goldsmith brings startingly to life in depicting the astonishing, languid Reginald Claypoole Vanderbilt, "little" Gloria's father. Born in 1880, the fourth son of Cornelius Vanderbilt II, this high-rolling gentleman required solid gold nameplates for each of his 60 thoroughbred horses, dropped $120,000 at roulette in one evening and bought hundreds of automobiles. Goldsmith gives us a wonderful glimpse of the prodigal millionaire taking a spin: "The pudgy Reggie Vanderbilt was a startling sight speeding down country roads in his roadster, a bull terrier seated at his side on the open front seat. The dog wore leather leggings, a leather coat, and driving goggles that matched Reggie's own." One way or another Vanderbilt ran through $25 million in capital and income between his 21st birthday in 1901 and 1915 when he was charged with falsifying his tax returns.

So it was, when Reggie finally drank himself to death in 1925, that Gloria Mercedes Morgan Vanderbilt, the beautiful young inconnue who had contracted a brilliant marriage at 18, found herself a 20-year-old widow with a taste for luxury, a baby daughter and no money (relatively speaking). Her daughter Gloria, however, inherited a $2.5 million trust fund which came complete with guardians (Gloria mere was still under age herself) who insisted that every penny be spent on the maintenance of the little girl -- and be strictly accounted for.

Little Gloria . . . Happy at Last -- an awkward title -- is no tale of glittering young love, but rather one of an intensely complicated dance of misunderstanding, greed, extravagance, law, servants, hangers-on and high society on both sides of the Atlantic. Tracking Gloria after Reggie's death is like chasing a firefly: "Six months was the longest time she stayed in any one place after her daughter's birth. In one year she made twelve ocean voyages and visited in six countries; during the year 1929 she employed twenty servants and maintained residences in England, France and Switzerland." Goldsmith chronicles Gloria's travels in addictive detail as well as her intrigues, her ill-fated attempt to marry Prince Gottfried Hohenlohe-Langenburg, her twin sister Thelma's prolonged affair with Edward, Prince of Wales (she made the mistake of introducing him to her friend Wallis Simpson). All this, and little Gloria went too.

And what of her? She emerges as a predictably pathetic figure despite her lineage and riches. Ignored and resented by her giddy mother, smothered by her overprotective nurse, it is hardly surprising that she ended up a ten-year-old hypochondriac with a tendency to hysteria. No wonder either that this child at long last found the stability and security she craved at Wheatley Hills, the Long Island estate of her aunt, Gertrude Vanderbilt Whitney, the fabulously wealthy widow of Harry Payne Whitney. Dumped there by her restless mother, little Gloria -- not to mention her devoted nurse "Dodo" Keislich -- was determined to stay.

This determination was to prove crucial to Little Gloria's centerpiece: the prolonged and bitter battle between Gloria Vanderbilt and Gertrude Whitney for custody of little Gloria. The court records alone contain 7,000 pages of testimony -- a goldmine for Goldsmith.

It is a measure of Goldsmith's skill as a storyteller that, though many readers already know who won the custody case, the suspense mounts inexorably as witnesses testify to "fast" goings-on in European society, where one bill read "Champagne for Marchioness of Milford Haven's feet," to rat-infested apartments and a child with a $4000-a-month allowance (this is the 1930s) who was at times without adequate clothing and whose nurse remained unpaid for months at a time.

The turning point of the trial came when Gloria appeared before the judge and dramatically claimed her mother had "never been nice to me," and "I was afraid she'd do something to me," "I hated her." What had happened to the child who had written to her mother three years earlier "I hope you are very well. I long to see you back again . . ."?

Early on in her research Goldsmith became enamoured of a theory, highly possible but basically unprovable, that little Gloria's sudden hostility and fear of her mother was a direct result of the concurrent publicity attached to the kidnapping of the Lindbergh baby. Goldsmith herself remembers fearing kidnapping as a child: the ladder at the window, the shallow grave in the woods. She feels that little Gloria, aware of her wealth and of the conflict surrounding her, became convinced that her mother wanted to murder her for money. It's an insightful and fascinating explanation, but it remains after all a theory and the endless parallels insisted on by the author finally come between the reader and the bizarre human drama that is unfolding. It seems just as likely that the child's erratic and unbalanced maternal grandmother, Laura Kilpatrick Morgan, who betrayed her daughter and talked constantly of the possible murder of little Gloria, may have been equally responsible for the child's attitude.

Terrified of her own mother, little Gloria clung to Auntie Ger. Gertrude Vanderbilt Whitney, standing stiff and polite in the witness box, is perhaps the most fascinating character on Goldsmith's crowded stage. A reserved yet intense woman, she played the matriarch on her estates and in society, yet longed to be an artist, to be judged on her merits. She became, in fact, two people "the perfect lady in the House of Worth ball gown and the $600,000 Payne pearls, and the passionate bohemian in an exotic costume dancing barefoot in the moonlight." She founded the Whitney Museum of America Art as a showcase for artists like Thomas Hart Benton, Edward Hopper, John Sloan, and George Luks who were still scorned by the established art world. In a curious exchange at the custody trial, list of so-called immoral works of art on display at the Whitney Museum was entered as evidence by Gloria's lawyer in a vain effort to blacken Gertrude's character. Justice John Francis Carew's attitude to contemporary art was clearly revealed as he attempted to interpret this piece of evidence: "Of course," he said, "the circumstances are very different from having dirty pictures thrown around the house . . ."

Little gloria is like a Breughel canvas, teaming with characters and events all moving in different directions. It is impossible for either author or reader to keep them all in clear focus. Everywhere you look is a juicy story, a new protagonist: Justice Carew himself, a rigid Catholic with an antipathy for aristocrats and their titles, out of his depth in all directions but determined to emulate Solomon; the repressed, spiteful yet truly devoted nurse Keislich; Gloria's lawyer, Nathan Burkan, half in love with his client, pursued by anti-Semitism, always asking one question too many in his eagerness to crush his adversary, and who in the end literally gave his life to her cause; the Marquess and Marchioness of Milford Haven, their closets bursting with skeletons and dark sins, but shielded by reverence for any royal connection.

With the drama, scandal, money, and screaming headlines, Goldsmith has brought alive the color, the extravagance and the decadence of America before the IRS was king. But even though she gives us a ten-course banquet of Vanderbilts and Whitneys, we are left -- hard to believe -- wanting more. Little Gloria is now 56, a widow who has been married four times, a name on the hip pockets of the trendy. She wouldn't talk. For her, reportedly, it's all still too painful. So, even the indefatigable Barbara Goldsmith can't tell us how it all seemed to a ten-year-old heiress, whether in fact she read the scary headlines, whether she saw murder in the eyes of her unheeding mother.