“Previous generations bought Renoirs and Cézannes,” Dan Lanigan says. “We’re buying stormtrooper helmets and Ghostbusters proton packs.” The burly TV producer is referring to the obsessive (and costly) pursuit of prop collecting. “This is the fine art of my generation.” It used to be an underground hobby. People did it, but nobody talked about it—not only because it was embarrassing to admit that you coveted Charlton Heston’s slave collar from Planet of the Apes but also because, since such things were studio property, it was illegal to own them. Shady studio insiders and a cabal of collectors struck deals in private. That all changed in 1970, when MGM cleared some clutter from its soundstages with a three-day auction. Among the frayed costumes and antique furniture that hit the block were two of the most important sci-fi props ever made: the proto-steampunk contraption from the 1960 film adaptation of H. G. Wells’ The Time Machine, and the miniature model of the United Planets Cruiser C-57D, better known as the Forbidden Planet flying saucer. The time machine sold for almost $10,000, and while there’s no record of what the silver saucer went for then, it changed hands eight years ago for $76,700. Since MGM’s auction, prices for the best sci-fi props have routinely hit six-figures. In October 2015, the miniature Rebel blockade runner ship from Star Wars: Episode IV pulled down $450,000. This very expensive hobby is about more than snatching up the coolest specimens. It’s about lost youth, self-identification, preserving the past, and—though most collectors won’t admit it—hero worship and secret cosplay. There are some things in life more thrilling than watching your favorite movie late at night while clutching a screen-used prop from the same flick in your trembling, sweaty palms, but it’s a very short list.