The nine-day-long European fine art fair (TEFAF), which opened in Maastricht on March 7, provided the most astonishing evidence yet that the art market is governed by rules that set it apart from any other sector of the economy. In the morning of the private-viewing day that traditionally precedes the start of the most important art fair in the world, professionals could not quite conceal their unease. The worldwide turbulence in the equity markets was getting worse, and the drastic credit squeeze particularly worried dealers selling high-priced paintings. The most naturally optimistic among them never imagined what would happen in the next few hours: Not only was the crowd that poured in bigger than ever, but it quickly became clear that buyers had never been quite so bullish at the top echelons of the market.

The experience of one London dealer, Johnny Van Haeften, whose connoisseurship in Dutch and Flemish painting makes him the world leader in the field, revealed to the full the galvanizing effect that the fair had on the visitors’ eagerness to spend despite an extremely difficult economic environment. At the private viewing alone, Van Haeften sold five paintings. Four of these, when displayed in his otherwise highly successful winter show in London last December, had failed to find takers even though the fully illustrated catalogue distributed across the world had increased their exposure. In the sedate atmosphere of a gallery, however, no quick decisions need to be taken, while at Maastricht even a beginner would have realized that with all the well-heeled collectors and museum officials walking around, this was neither the place nor the moment to shilly-shally over the acquisition of a coveted work.

The first of Van Haeften’s pictures to go was Pieter Brueghel the Younger’s Massacre of the Innocents. Inspired by the compositions on the subject done by the artist’s father, Pieter Brueghel the Elder, it is one of no fewer than 14 versions recorded by Klaus Ertz in his catalogue raisonné of Pieter the Younger’s oeuvre. It is, however, the most accomplished of these. Demand for both Brueghels, father and son, is huge. At €2 million ($3 million), the painting went in no time.

The four other pictures the dealer sold that evening were all rarities for one reason or another. Jan van Goyen’s view of the Haarlemer Meer, painted in the 1640s and priced at €1.1 million ($1.7 million), is his only seascape where lightning pierces the darkness of a tempestuous sky over agitated waters.

For art historians, the ultimate rarity that night was Jan Brueghel the Elder’s Aeneas and the Sibyl in the Underworld, a Brueghelian variation on hell using a Greek mythological theme. Done in extraordinarily fine detail on copper, the impeccably preserved picture is dated 1593, which makes it the earliest dated work by the artist. Brueghel painted it at age 25 during his stay in Italy, from 1589 to 1596—hence its very Italianate style. Undaunted by the picture’s sexual imagery with sadistic undertones, a collector picked it up for €3.9 million ($5.8  million).

Ottmar Elliger the Elder’s 1666 still life of fruits inhabited by butterflies and a grasshopper, rendered in starkly contrasting light and shadow, was also highly unusual. Elliger’s work is seldom seen in the market. With its sculptural handling and an atmosphere of deep forest mystery that harks back to the 16th-century Danube school, the painting is typical of German art, whose originality at that period has yet to be acknowledged. At €165,000 ($255,000), it was a giveaway.

The last of Van Haeften’s private-viewing sales was another gem: Anthonie De Lorme’s 1667 view of the interior of the Laurenskerk (Saint Lawrence Church), in Rotterdam, showing the tomb of Admiral Witte Corneliszoon de With. Signed and dated, the picture was unpublished until the dealer reproduced it on the cover of his London catalogue. The frontal view of the tomb is unusual, and the play of sunlight on the off-white wall is marvelous. The asking price of €2 million ($3 million), while rather high for De Lorme, was low for a masterpiece made more exciting by its iconography, which raises an intriguing historical riddle: A Turk wearing the distinctive Ottoman turban stands talking to a Dutch gentleman in front of the funerary bas relief of the admiral, who is shown reclining under the figures of Neptune and Mars. Does this symbolize a warning from the Dutch to the Turkish enemy, then entrenched in most of southeastern Europe and constantly challenging the western European navies in the Mediterranean?

Those early sales were just a beginning. By the end of the fair, on March 16, Van Haeften had sold 20 pictures worth a total of about €14 million (more than $20 million). How does he think Maastricht 2008 compared with the previous year’s event? “Definitely better,” Van Haeften answers in a flash. “There were more people, including more Americans, and many more were focused on buying.”

What took place could be described as a general creaming off of the best that was to be seen of most schools. William Noortman of Maastricht, who had the honor of stepping into the shoes of his late father, the great Robert Noortman, sold that evening a marvelous seduction scene by Caspar Netscher, the German born painter who spent his career in Holland. Bought by Noortman Sr. in partnership with Van Haeften and another London dealer, the picture had been offered in Van Haeften’s December show. At Maastricht, Noortman negotiated the €2 million ($3 million) masterpiece within hours.

The skimming process occurred at every financial level. Noortman had discovered two unrecorded miniatures by the 16th-century Flemish Mannerist Pieter Schoubroeck. One of the paintings, which the dealer says depicts Saint Paul having fallen from his horse at the sight of a celestial apparition—a Hebrew inscription visible on the sun globe has yet to be read by a scholar with a knowledge of the language—is ravishing. The other deals with the mythologic theme of Perseus and Andromeda. At €48,000 ($74,100), the rare discovery was a bargain.

Another prize at Noortman’s stand, also tagged €48,000 ($74,100), was one of the most delightful pictures by Eugène Carrière to be seen anywhere. A young girl is portrayed pouring tea in a hazy light. The French painter, evidently aware of the art of Manet and Degas, must have done it in the early 1880s. A steal at the price, it was picked up by a young Dutchman.

If any trend emerged at Maastricht, it was a longing for works that make you dream either through their intensely poetic character, like Schoubroeck’s biblical scene, or through their unbridled fantasy. Roman Herzig, the owner of the Galerie Sanct Lucas, in Vienna, scored on both counts. An enchanting composition of fruits piled on a stone ledge, executed in 1690 in chiaroscuro and signed and dated by Rachel Ruysch, the grande dame of late Dutch still-life painting, was unpublished. It was not exactly cheap at €800,000 ($1.2 million). But it was a discovery, and it went at once. So did an intriguing unsigned picture. The extravagant scene, painted by a highly skilled French artist in the 1770s, shows a woman in a white muslin dress being winched down the face of a cliff as a group of men watch from the top. Others at the bottom gesticulate excitedly, untroubled by the splashing of a mountain torrent. One detail that Herzig had not considered may help in eventually identifying the painter: A small section of the woman’s sash is crudely indicated, in contrast with the carefully polished execution of the rest of the picture, which is in excellent condition. This suggests that its creation was interrupted by some incident, perhaps the artist’s death—a circumstance that would also account for the absence of a signature, surprising in an elaborate work by a highly qualified practitioner. Another clue is the event depicted. Too specific to be purely imaginary, it must relate either to a real-life occurrence or to some literary narrative that had struck the popular imagination at the time. It will be up to the French collector who paid €450,000 ($694,800) for the mystery picture to solve the riddle.

Perhaps the most poetic work in the fair was the portrait of a young woman who has just dozed off, her head thrown back. Displayed by Clovis Whitfield of London, the picture is by Carlo Francesco Nuvolone, a 17th-century artist. Nuvolone may not be the most important master of the Italian school, but this work was a small gem. At €220,000 ($344,900), it proved irresistible.

The fact that the Nuvolone was previously unknown made it doubly attractive. This underlines the importance of unpublished works of art in the success of Maastricht as a whole. Indeed, the excitement of discoveries is one of the factors that allow the art market to function differently from the general economy—nothing is more exhilarating to a collector or a museum curator than seeing a work that reveals an unsuspected side to an artist or to a whole school.

If a prize were to be awarded for the biggest surprise at Maastricht, it might go to the Jan Steen brought by Simon Dickinson and James Roundell. The Dutch artist is renowned for his interior scenes, mostly smoky taverns with rough-looking drinkers and lewd women,  painted in a small format. The last thing connoisseurs expect from him is a large picture with a mythological subject. Dickinson and Roundell’s Steen, The Sacrifice of Iphigenia, measuring 53 by 68 inches, was done in a thoroughly Italianate style utterly unlike the artist’s usual grim realism. Yet no shadow of a doubt hangs over the painting, which is signed and dated 1671. It was displayed at the Rijksmuseum, in Amsterdam, for more than four decades before being returned, in 2006, to the heirs of the famous Jewish collector-dealer Jacques Goudstikker. Although the picture is well known to art historians, it did not receive remotely as much attention in the rich surroundings of one of the two greatest museums of Dutch painting (the other being the Mauritshuis, in The Hague) as it did at Maastricht. At €8 million ($12.4 million), the painting was quickly sold.

Some of the previously unknown works displayed at Maastricht came with remarkable stories that have remained unpublicized. One such tale attaches to the small interior scene by Adriaen Brouwer shown by Bruce Livie, the Munich-based American dealer who runs the Arnoldi-Livie Gallery in partnership with his wife, Angelika Arnoldi-Livie. The Flemish Brouwer, who died in 1638, belonged to the first generation to produce such paintings. In Livie’s small panel, an elderly man has fallen asleep in his chair while a coarse-looking character dallies with a tavern wench in the background, spied upon by a voyeur grinning down at them through an opening in the wall.

The panel came to the Munich dealer by a circuitous route. It first surfaced in a small sale in Brussels, to which it was reportedly consigned by the Bergeyck family after being rejected by a major auction-house specialist as the anonymous work of a minor artist. A professional with a sharp eye bought the scene and took it to Sotheby’s in Amsterdam, where it was recognized as a Brouwer and put up for sale as such. The painting had, however, been tainted by its earlier tribulations, which were known to several professionals, and Livie faced only mild competition when he bid for it.

Having bought it, the dealer set about researching his Brouwer. A critical clue was an early 20th-century label on the panel’s back identifying the then owner as a count de Bergeyck. A search through early sources revealed that in the 17th century, a de Bergeyck had been the second husband of the widow of Peter Paul Rubens, Hélène Fourment, who had inherited all the famous Flemish master’s art holdings. Rubens, who doubled as a dealer and art broker, owned 13 Brouwers when he died. It became clear to Livie that his acquisition was almost certainly one of these. The last step in his sleuthing endeavor was to submit the panel to the most accomplished expert on Brouwer: Konrad Renger, who had recently retired as curator of Dutch and Flemish paintings at the Alte Pinakothek, in Munich, where he had organized a great retrospective of the artist in 1986. Renger confirmed the authenticity of Livie’s picture.

As is often the case with paintings that have stayed in the same family for centuries, the panel is superbly preserved. On March 7 at TEFAF, the curator of a European museum pounced on the €750,000 ($1.2 million) picture, made doubly important by its historic provenance.

Museums generally take much longer to reach a decision on purchases. The sales of two pictures were being negotiated as the fair ended.

One of these, brought by the New York Old Masters dealer Richard Feigen, illustrates the role chance plays in art-historical scoops. Feigen told me that he had walked into the Hôtel Drouot, the Paris auction house, and come across a Neoclassical painting covered in grime. He had not been aware that the picture was being sold that week, nor had he read the catalogue entry for it. The signature of François-André Vincent and the date 1784 were both visible on the large canvas, and the dealer bought it. Back home, he embarked on some digging. His researcher, Ann Guité, found a description of the painting in the brochure of the 1785 Paris Salon, accompanied by an engraved reproduction. French Neoclassicism has been exciting art historians for a good decade. As TEFAF closed, four museums were expressing interest in the Vincent, with its €550,000  ($849,200) price tag.

On Clovis Whitfield’s stand, another picture caused a similar sensation among institutions. The large Caravaggesque composition by Simon Vouet was executed during his stay in Rome, in the 1620s. Its loan has been requested for a traveling exhibition of the French master’s Italian oeuvre that is to be held in Nantes and Besançon, France. The picture will no doubt have found a home by then, if not long before.

Discoveries, although less frequent in Impressionist and modern masters, have the same stimulating effect wherever they occur. One of the foremost connoisseurs of Impressionism is the American dealer Waring Hopkins, who runs the Paris gallery Hopkins-Custot with his business partner, Stéphane Custot. Hopkins took to Maastricht a previously unrecorded portrait by Berthe Morisot. This likeness of a young girl was executed in the early 1880s, when the artist had already broken with Manet and had not yet fallen under Renoir’s influence. Highly advanced in its brushwork, it is deeply stirring in its psychological insight, even though Hopkins states, with unconvincing modesty, that he has seen better Morisots. At €600,000 ($926,400), it was easily the greatest buy in Impressionist art at the fair. The painting could go straight into a museum, but a collector jumped first.

It is the possibility of finding such unexpected treasures that keeps TEFAF going strong and that allows the market for art to retain a vibrancy that no other market can ever match. At the lower quality level, it was another story. When neither novelty nor fashion were there to boost sales, the outcome fell short of expectations. That lack of enthusiasm will be worrying art dealers and auction-house specialists alike in the foreseeable future.

Contrary to a widely held belief, big profits depend not on how masterpieces and art-historical rarities sell but on the ease with which middle-of-the road pictures and objets d’art find buyers. There is one very simple reason: These by definition, represent the greatest part of what is available.

"The Mysteries of Maastricht" originally appeared in the May 2008 issue of Art+Auction. For a complete list of articles from this issue available on ARTINFO, see Art+Auction's May 2008 Table of Contents.