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in 1690 in chiaroscuro and signed and dated by Rachel Ruysch, the grande dame of late Dutch still-life painting, was unpublished.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.