In the cutthroat world of the art trade, there was one principle that was supposed to be sacrosanct. Provenance, the written record of a painting's chain of ownership, was everything. Theoretically, dealers did not sell paintings without a proper provenance, collectors did not buy them, and no decent restorer would ever lay hands on a picture without knowing where it had been and under what conditions it had hung. But after many years of conducting provenance research, Gabriel had learned never to be shocked by the secret lives led by some of the world's most sought-after works of art. He knew that paintings, like people, sometimes lied about their pasts. And he knew that, often, those lies revealed more than the so-called truths contained in their printed pedigrees. All of which explained his interest in De Vries Fine Arts, purveyors of quality Dutch and Flemish Old Master paintings since 1882.

Occupying a stately if somewhat sullen building overlooking Amsterdam's Herengracht canal, the gallery had always presented itself as the very picture of stability and good manners, though a brief glimpse into the darkest chambers of its past would tell a markedly different story. Regrettably, none was darker than its conduct during the Second World War. Within weeks of Holland's capitulation, Amsterdam was inundated by a wave of Germans looking for Dutch paintings. Prices soared so quickly that ordinary citizens were soon scouring their closets for anything that might be regarded as an Old Master. The De Vries gallery welcomed the Germans with open arms. Its best customer was none other than Hermann Goring, who purchased more than a dozen paintings from the gallery between 1940 and 1942. The staff found Goring to be a shrewd negotiator and secretly enjoyed his roguish charm. For his part, Goring would tell colleagues in Berlin that no shopping spree in Amsterdam was complete without a stop at the exquisite gallery along the Herengracht.

The gallery had also played a prominent role in the history of Rembrandt's Portrait of a Young Woman. Of the three known times that the painting changed hands in the twentieth century, two of the sales had been conducted under the auspices of De Vries Fine Arts. The first sale had occurred in 1919, the second in 1936. Both had been private, meaning that the identity of buyer and seller were known only to the gallery itself. Under the rules of the art trade, such transactions were to remain confidential for all eternity. But in some circumstances—with the passage of enough time or for the right amount of money—a dealer could be cajoled into opening his books.

Gabriel entrusted that delicate task to Julian Isherwood, who had always enjoyed a cordial professional relationship with the De Vries gallery despite its questionable past. It took several hours of heated telephone negotiations, but Isherwood finally convinced Geert de Vries, great-grandson of the founder, to surrender the records. Isherwood would never tell Gabriel the exact price he had paid for the documents, only that it had been steep. "Remember one thing about art dealers," he said. "They are the lowest of God's creatures. And economic times like these bring out the worst in them."

Gabriel and Chiara monitored the final stages of the negotiations from a charming suite at the Ambassade Hotel. After receiving word that the deal had been finalized, they left the hotel a few minutes apart and made the short walk along the Herengracht to the gallery, Chiara on one side of the canal, Gabriel on the other. Geert de Vries had left photocopies of the records at the front desk in a buff envelope marked ROSSI. Gabriel slipped it into his bag and bade the receptionist a pleasant afternoon in Italian-accented English. Stepping outside, he saw Chiara leaning against a lamppost on the opposite bank of the canal. Her scarf was knotted in a way that meant she had not noticed surveillance of any sort. She followed him to a cafe in the Bloemenmarkt and drank hot chocolate while he worked his way laboriously through the documents.

"There's a reason why the Dutch speak so many languages. Their own is impenetrable."

"Can you make it out?"

"Most of it. The person who bought the painting in 1919 was a banker named Andries van Gelder. He must have been hit hard by the Great Depression. When he sold it in 1936, he did so at a considerable loss."

"And the next owner?"

"A man named Jacob Herzfeld."

"Are Dutch boys ever named Jacob?"

"They're usually called Jacobus."

"So he was Jewish?"

"Probably."

"When was the next sale?"

"Nineteen sixty-four at the Hoffmann Gallery of Lucerne."

"Switzerland? Why would Jacob Herzfeld sell his painting there?"

"I'm betting it wasn't him."

"Why?"

"Because unless Jacob Herzfeld was extremely lucky, he probably wasn't alive in 1964. Which means it's quite possible we've just discovered a very large hole in the painting's provenance."

"So what are we going to do now?"

Gabriel shoved the documents back into the envelope.

"Find out what happened to him."

Portrait of a Young Woman, oil on canvas, 104 by 86 centimeters, was painted in a large house just west of Amsterdam's old center. Rembrandt purchased the property in 1639 for the price of thirteen thousand guilders, an enormous sum even for a painter of his stature and one that would eventually lead to his financial undoing. At the time, the street was known as Sint Antonisbreestraat. Later, due to a change in the neighborhood's demographics, it would be renamed Jodenbreestraat, or Jewish Broad Street. Why Rembrandt chose to live in such a place has long been a matter of debate. Was it because he harbored a secret affinity for Judaism? Or did he choose to reside in the district because it was home to many other painters and collectors? Whatever the case, one thing is beyond dispute. The greatest painter of Holland's Golden Age lived and worked among Amsterdam's Jews.

Shortly after Rembrandt's death, a number of large synagogues were constructed near the opposite end of Jodenbreestraat around the Visserplein and Meijerplein. The redbrick buildings somehow managed to survive the Nazi occupation of the Netherlands, though most of the people who prayed there did not. Nestled within a complex of four old Ashkenazi synagogues is the primary keeper of this terrible memory, the Jewish Historical Museum. After passing through the magnetometer at the front entrance, Gabriel asked for the research facility and was directed to the lowest level. It was a modern space, clean and brightly lit, with long worktables and an internal spiral staircase leading to the upper stacks. Given the lateness of the hour, it was empty except for a single archivist, a tall man in his early forties with reddish blond hair.

Without going into specifics, Gabriel said he was looking for information about a man named Jacob Herzfeld. The archivist asked for the correct spelling, then walked over to a computer terminal. A click of the mouse brought up a page for a database search engine. He entered Herzfeld's first and last name and clicked again.

"This could be him. Jacob Herzfeld, born in Amsterdam in March 1896, died at Auschwitz in March 1943. His wife and daughter were murdered at the same time. The child was only nine years old." The archivist glanced over his shoulder at Gabriel. "They must have been rather well-to-do. They lived at a good address on Plantage Middenlaan. It's quite close to here, just on the other side of Wertheim Park."

"Is there a way to tell if any members of the family survived?"

"Not using this database, but let me check our files."

The archivist disappeared through a doorway. Chiara roamed the stacks while Gabriel sat down at the computer and scrolled through the names of the dead. Salomon Wass, born in Amsterdam, 31 May 1932, murdered at Sobibor, 14 May 1943...Alida Spier, born Rotterdam, 20 September 1915, murdered at Auschwitz, 30 September 1942...Sara da Silva Rosa, born Amsterdam, 8 April 1930, murdered at Auschwitz, 15 October 1942...They were but three of the 110,000 Dutch Jews who had been sealed into freight cars and dispatched eastward for murder and cremation. Only one-fifth of Holland's Jews survived the war, the lowest percentage of any Western country occupied by the Germans. Several factors contributed to the lethality of the Holocaust in Holland, not least of which was the enthusiastic support given the project by many elements of Dutch society. Indeed, from the Dutch police officers who arrested Jews to the Dutch rail workers who transported them to their deaths, Dutch citizens were active at nearly every stage of the process. Adolf Eichmann, the managing director of the Final Solution, would later say of his local helpers, "It was a pleasure to work with them."