When stains had to be cleaned from a mosaic that once decorated a lavish pleasure vessel from the first century, they were not remnants from the debauched revelries that the murderous and sex-crazed Roman Emperor Caligula used to hold on the ship.
Instead, they were vestiges of modern, everyday life from a New York City apartment almost 2,000 years later.
But exactly how the mosaic ended up as a coffee table in a Park Avenue living room is still something of a mystery.
The mosaic is a four-and-a-half square-foot geometric piece made up of rich green and white marble and purple-red porphyry, a type of rock textured with crystals that was frequently the choice of Roman emperors.
When Caligula was assassinated in A.D. 41 after ruling for only four years, his two ships were sunk where they sat, in the middle of Lake Nemi, a small volcanic lake southeast of Rome.
Over the ensuing centuries, several attempts had been made to raise the opulent ships from the lake.