Deep in the belly of this whale, I feel not submerged but lifted by an old feeling. I recognize it from my wasted youth as a wannabe historian, when I was certain that the next file I opened in some presidential library would produce the magic slip of paper, the telltale photograph, the confidential memo that would reveal all. There was no telling what one might find in one of those dusty cartons.

As a graduate student researching the national political ambitions of Huey Long, I visited the old Roosevelt mansion at Hyde Park, N.Y., and came across an exchange of memos between FDR and his campaign manager, James Aloysius Farley, about the possibility of the Kingfish's running for president in 1936.

Farley wasn't at all concerned. FDR was-another confirmation of his political astuteness. But he needn't have worried; Huey was shot down in Louisiana's state Capitol in September of '35. We'll never know how well he would have done as a presidential candidate, but he could scarcely have fared any worse than the Republican candidate that year-hapless Alf Landon, who found himself up against The Great Communicator of his era.

Here in the innards of the Clinton Library, the past towers over us. The library's more than hospitable director, David Alsobrook, shows us the mountains of still undigested boxes and crates-and a system of compact shelving that squeezes reams of historical documents into the smallest space, like some giant accordion. Who knows what one might find tucked away here?

Even if the hope of finding the one clue that explains everything is never fulfilled, there is nothing quite like the search for it. We could have been in the final scene of "Citizen Kane," the classic film modeled on the life and larger-than-life times of William Randolph Hearst, searching through the detritus of history in the cavernous bowels of Charles Foster Kane's pharaonic mansion, hoping to discover the significance of his last, enigmatic word: Rosebud.

History can be one long search for a moment of insight. In Robert Penn Warren's "All the King's Men," Jack Burden finally tracks down the last letter from Mortimer L. Littlepaugh, Esq., which reveals all. "For nothing is lost, nothing is ever lost," says Jack.

But finding the key to it all isn't easy. There are many names for this hunt: research, obsession, calling and there are few better places to pursue it than deep inside a presidential library, or in an old Mobil gas station stranded in time.