'Supernatural': Sexy. Scary. Over?

In the intense universe of fandom surrounding Supernatural — the CW series that follows the chisel-jawed Winchester brothers as they drive around the country snuffing out demons — there are ''Sam girls'' and ''Dean girls.'' Websites chronicle every scrap of minutiae (including the fellas' sweet ride, a '67 Chevy Impala), and bloggers dig around casting directors' sites looking for snippets of scenes to post online (they've even managed to spoil entire scripts). There's also a unique and very creepy subset of romantic fan fiction dedicated to siblings Sam (Jared Padalecki) and Dean (Jensen Ackles) called ''Wincest'' — the less said about it the better. One creative fan actually showed up on set in an orange vest, pretending to be a production assistant. ''They gave her a walkie-talkie!'' recalls Ackles. ''She worked the entire day there until somebody finally figured it out. Obviously now they've stepped up the protocol.'' Meaning, the stars have a bodyguard when they're working. Says Padalecki, ''I guess the network or the studio said, 'We [only] have two guys on this show. We'd better protect them.'''

It might be time to beef up the security detail even more, because the Supernatural cult is swelling. Sure, the show may not crack the top 10, or even the top 80 — ''You go to a dinner party and someone asks you what show you work on and you say 'Supernatural,' and they've never heard of it,'' says creator/exec producer Eric Kripke. ''Then they say, 'What network is it on?' and you say 'The CW,' and they've never heard of it'' — but lately it's been making almost otherworldly gains in viewership. Season 4, which has centered on the brothers battling angels as well as their usual demon enemies, is up an impressive 13 percent over last year, with new episodes averaging 3.3 million viewers a week — and that's against Thursday-night stalwarts Grey's Anatomy and CSI. All those new Supernatural acolytes, however, may find themselves wishing they'd showed up sooner: The cast and crew's ''godfather,'' executive producer and director Kim Manners (The X-Files), passed away in January; Padalecki, 26, and Ackles, 31, are exhausted; and Kripke has long maintained that he wants the series to last only five seasons — that's one more, then they're done. As Kripke told his writers at the beginning of this season, ''Let's be bold. Let's delve into the stories headlong. Let's not tap-dance around them because we're scared, or because we have to save something for tomorrow. Because we don't know if there will be a tomorrow