Doctor Who has been running since 1963, and it’s something of a national treasure in the U.K. But it wasn’t always so cherished — more than a third of the episodes, 132 hours’ worth, were thoughtlessly exterminated by BBC apparatchiks. Most of the early episodes were shot on 2-inch, 405-line black-and-white videotape, but the bulk of seasons one through eight were systematically “wiped,” or erased, to make room in storage. “It was just another TV show to them,” says Whovian historian Richard Molesworth. “There was no inherent worth in it.”

But it turns out that you don’t need a time-traveling Tardis to glimpse some of these deleted classics: The BBC sold video-to-film transfers of early seasons to foreign markets, and those 16-mm reels have turned up in places like Nigeria, Cyprus, and Hong Kong. “In the ’80s, two or three episodes would be found a year,” Molesworth says. “But only two episodes have been found in the past 10 to 15 years.” Any celluloid still out there is in risk of deteriorating.

Fans are now reconstructing episodes using surviving audio tracks and photos that people snapped of their telly screens. They’re spiced up with surviving film clips that Australian censors once snipped for being too racy.