In the early morning hours of March 18, 1990, two men dressed as Boston police officers talked their way into the Isabella Stewart Gardner Museum and carried out one of the most valuable art thefts in history. Over the next 81 minutes, they restrained the guards and removed 13 works, including masterpieces by Vermeer, Rembrandt, and Degas. The stolen collection is now commonly valued at hundreds of millions of dollars, yet not a single work has officially been recovered. More than three decades later, empty frames still hang inside the museum where some of the paintings once stood. This is the story of a remarkably simple robbery that became one of the art world’s greatest unsolved mysteries.