Would you knowingly destroy a portion of one masterpiece in hopes of finding another of even greater value? Art historians are wrestling with this question, due to an ongoing project that sounds like it leapt from the pages of "The Da Vinci Code." The colossal frescoes in Florence's Palazzo Vecchio, painted by 16th-century artist Giorgio Vasari, seem to contain a treasure map, complete with a riddle that a charismatic engineer-turned-art historian is about to crack.

As you step out of the blinding Florentine sunlight and into the terracotta-scented Palazzo Vecchio, you will encounter the soaring walls of a vast meeting hall, Il Salone dei Cinquecento. This hall is painted with larger-than-life-size frescoes of riding and ranting warriors, enormous battle scenes that show the military triumphs of the Medici family, painted in 1563 by Vasari.

But buried beneath one of the four frescoed walls may lie a treasure of far greater importance - one that has not been seen for five centuries: a lost painting by Leonardo da Vinci.

In 1505, Leonardo began painting one wall of the meeting hall, a tangle of swords and horsemen called "Battle of Anghiari." He was called away shortly after he had begun, and we know what his unfinished battle scene looked like only from a copy made by Rubens.

The man hunting the lost Leonardo, Maurizio Seracini, has been called the "real Indiana Jones." An art-world celebrity, sponsored by National Geographic, he runs two laboratories, one at UC San Diego, the other in Florence, Italy. He has studied more than 2,500 artworks and monuments using advanced new technologies, many of which he himself adapted and developed.

Back in 1975, Seracini noticed a tiny bit of text hidden within Vasari's frescoes in the Salone dei Cinquecento. Throughout the entire room, on one frescoed wall, which is 177 feet long, Vasari had painted exactly two words. Cerca trova. (Seek and you shall find.)

Seracini and many leading Leonardo scholars believe this to be a real clue from Vasari, indicating that he somehow preserved Leonardo's work - that this lost painting is hidden beneath a false wall onto which Vasari painted his own frescoes.

Delayed by Italian government red tape, it was only in 2006 that Seracini finally discovered a 1.5-inch hollow gap between the back of Vasari's frescoed wall and a second wall behind it. This double wall, which Vasari must have built when he painted the frescoes, is unheard of, and has no architectural or structural rationale. Further, the gap is only behind one of Vasari's four frescoed walls - the one with the words cerca trova written on it.

On March 12, UCSD announced that, by drilling through the Vasari fresco, Seracini's team found a black pigment that matched pigment used in Leonardo's Mona Lisa, suggesting that something lies beneath after all. This is promising, because many fear that the priceless Vasari fresco is being partially destroyed during this investigation for naught. Important art historians have signed a petition to stop the investigation because it is damaging the Vasari, and may end up as a wild goose chase.

The search continues, as the art world eagerly awaits what would be the biggest discovery of the century. But if Seracini succeeds, then we are faced with one more puzzle: How do we reveal the entire Leonardo without destroying the Vasari that lies above it?

Noah Charney is the author of "Stealing the Mystic Lamb: The True Story of the World's Most Coveted Masterpiece" (PublicAffairs, 2010). He teaches art history and art crime for Brown University and the Association for Research into Crimes Against Art.