The tiny Simca 1000 Sedan puttered through the winding streets of a tony enclave near Israel’s presidential residence. The spring evening was warm, and the scent of flowers filled the air. The neighborhood was a calm oasis, away from the dust and tumult of the Old City. The streets were particularly empty after the Sabbath began on Friday, April 15, 1983.

The Simca drove along HaPalmach Street and stopped in front of a pale three-story building: the L. A. Mayer Museum for Islamic Art. The car idled. Broad stairs led up to the front door. White light flickered through a window in the front of the building—the guards were settling down to read and sleep.

The museum was famous for its collection of Islamic artifacts, but it was also home to a cache of rare timepieces, an assortment of pocket watches and mechanical ephemera so fine that many scholars considered it a mother lode of horology. The collection was kept in a gallery at the back of the building, and there, resting in a glass case unconnected to any alarm, lay what was likely the most expensive watch in the world: a priceless gold pocket watch designed for Marie Antoinette by legendary Swiss watchmaker Abraham-Louis Breguet. At the time of its commission in 1783, nobody had ever made a timepiece so complex and beautiful. In the intervening centuries, few had ever approached its artistry. The watch was known as the Queen.

The driver parked and approached a heavy iron gate. He ran a hand idly over the metal, listening and looking for guards or passersby. He was whippet-thin, with brown hair and a sharp, angular face. He had spent months preparing for this moment, training himself to work quickly and quietly.

When he was sure nobody was around, the man pulled a hydraulic jack from the back of his car. He fitted the jack between the metal bars and began cranking them far enough apart so that he could slip through. Using a rope ladder and hooks, he climbed about 10 feet up the side of the building and through an 18-inch-tall window that he opened with a screwdriver. Over the course of the night, he would steal valuable art objects and more than half the watch collection—including Marie Antoinette’s storied gold watch, the Queen.

Sometime before 10:30 am on April 16, 1983, after the trim thief had shuttled the last watch from the museum into his car, he slipped behind the wheel, turned the ignition, and vanished into the Jerusalem night, leaving behind only a mystery.

In the wake of the robbery, after the assessors tallied up all of the losses, the true scope of the theft became clear. For insurance purposes, they valued the collection at around $700,000, but the watches were each one of a kind. Desperate, the estate of the museum’s founder hired an investigator named Samuel Nahmias to search for the Queen. Nahmias was uniquely qualified for the position. A former Israeli army intelligence officer turned private investigator, he had already successfully recovered hundreds of thousands of dollars in gems and cash for his clients in the jewelry world.

Nahmias’ usual approach was to start with a suspect’s inner circle—family, close associates, lovers—in the hope that someone would have seen the loot and would buckle under the pressure and turn the perpetrator in. In this case, however, there was no solid suspect. So Nahmias checked auction houses and kept tabs on antiques dealers and collectors from Tel Aviv to Moscow to see if anyone had worked with the thief. He sent associates to Switzerland multiple times on tips that the watches had surfaced. But every lead hit a dead end.

The watches themselves were too well known to sell on the open market. Most were made by Breguet in the late 1700s and 1800s and were well documented—especially the Queen. Commissioned for Marie Antoinette allegedly by the man rumored to be her lover, Count Hans Axel von Fersen, the watch was to have all conceivable features in it, according to Breguet’s paperwork. Gold was to replace brass wherever possible. No limit was imposed on price or time of manufacturing. The name of the commissioner was left off the order.

The watch ultimately took 44 years to complete. In the interim, the French Revolution and the resulting European upheaval led to the death of both the man who likely commissioned the watch and its intended owner. (Marie Antoinette, of course, fell under the guillotine. Seventeen years after her death, an incensed crowd, convinced that von Fersen had conspired to assassinate Sweden’s would-be king, beat him to death in a Stockholm square.) Breguet died in September 1823. His son, a talented horologer in his own right, finished the masterpiece in 1827. It traveled in the coat pockets of a French nobleman and later ended up in the collection of Sir David Lionel Salomons, a British polymath who brought the first car shows to England and patented an idea for buoyant soap. Salomons left his watch collection to his daughter Vera, a globe-trotting nurse who settled in Jerusalem after World War I and later used her father’s money to build the museum—and to house his collection of watches.

What made Breguet’s work so significant was his skill as both a watchmaker and a designer. His creations have pristine faces, delicate hands that end in apple-shaped tips, and movements that appear as complex as a computer circuit. The Queen was at once immensely complicated—it had all the features of a cathedral clock in the space of a pocket watch—and beguilingly elegant. Breguet even made a clear crystal face that allowed the owner to see the movement of the gears underneath.

Breguet cased the Queen in gold. It featured a full perpetual calendar, a jumping hour hand that flicked from hour to hour instead of slowly rotating around the face, and an independent second hand that could be stopped or started at will. The watch even contained a metallic thermometer and a mechanism that chimed the time. Sapphires were used to reduce friction.

But the beautiful watch had vanished, and the investigation was going nowhere. Nahmias would invite convicted burglars with tips about the case for questioning and leave them in his lush garden for a few minutes. Unbeknownst to the crooks, Nahmias had bugged his garden with small microphones to a recorder, hoping they’d let something slip when he was out of earshot. He worked hard, but his ingenuity and his efforts were fruitless. Inviting convicted thieves was a clever tactic but could backfire, as prisoners would lie to get a meeting with Nahmias.

After a few years, Nahmias moved on. The trail was cold. The police had cataloged all possible suspects leaving Israel by air after the theft, hunted high and low in the criminal quarters, and Nahmias himself ticked off lead after lead with no results. Even museum employees originally suspected of having been in on the theft had easily passed lie detector tests. The museum slowly recovered.