It’s an opening scene right out of an Indiana Jones movie. Somehow I’ve made it into the Louvre while the legendary Parisian museum is closed, tiptoeing around its vast, echoey rooms made spooky by a lack of humanity. Trying not to let my sneakers squeal as I climb a set of stairs, I find my way to one of the oldest portions of this former home of French kings — all blood-red walls and ceilings coffered with gilt molding. I slip past tapestries (so many tapestries) depicting Louis XIV and his court, and golden side tables fit for Donald Trump’s White House, before entering the room containing the object I’ve come all this way to see.

In the center of the salon, before a looming painting of Louis XIV, sits a wide octagonal pyramid with mirrored sides about 20 feet across, its angles alien against its baroque surroundings. Atop is something equally out of this world: a 3½-foot-tall confection of crystal, delicate metal gears and glittering gold. Its base houses what appears to be the inner workings of a music box; in the middle, a clock — one that displays the hours, minutes, months, days, year, moon phase and time of sunrise and sunset. Somehow the seasons, solstices and stars in the sky are also discernible in this thing, which sits on a plate of lapis lazuli with mother-of-pearl inlay planets. On top of the clock there’s a golden man about 11 inches high, with zodiacal constellations etched into a glass dome around him.