The institution satirized in Gilbert and Sullivan’s Ruddigore (1887) was theater itself: the blood-and-thunder, mustached villain/virginal heroine/madwoman melodramas popular in their time. But unless you majored in 19th-century British stage history, the joke may be lost on you. “Flipping melodrama on its head—we don’t get it,” says Danielle Villegas, director of the Northwest Savoyards’ production, which opens this weekend in Everett. It’s a problem that has made this operetta one of the least-often staged in the G&S canon. In fact, the last time Ruddigore was done in the area was in 1997 by a group called the New Savoy Opera, which set the show in Pike Place Market for no other reason than that it was fun. (One of the characters was turned into a fruit-stand vendor; another, a sailor, wore a Mariners jersey.) Villegas’ solution: steampunk, that alternate-history cult aesthetic that retro-maps modern technology onto Victorian design, imagining the past as Jules Verne and H.G. Wells imagined the future. Think giant computers made of brass with manual-typewriter keyboards and all the gears showing. And goggles. Lots of goggles. The Gothicness of Gilbert’s original plot—an accursed young baronet is forced to commit a crime a day—is translated into a sort of “undergroundy feeling,” says Villegas, with shadowy pipes and ducts—the unseen bowels of urban life—replacing the ghost-and-castle vibe. Also, the production will slightly enhance those aspects of the libretto that are a little less prim than those of other G&S shows: “The dirty jokes, we let them be dirty,” Villegas says.