Since moving to UPN, Buffy the Vampire Slayer has pulled out all the stops to start viewers palpitating — and the best may be yet to come. Executive producer Marti Noxon tells TV Guide Online that the series soon will get an infusion of fresh blood.

For starters, former General Hospital ingenue Amber Tamblyn guest-stars in the Oct. 30 installment as Janice, a saucy classmate of the Slayer's kid sister, Dawn. "The episode revolves around Dawn and Janice and the misadventure that they get into," Noxon reveals. "It's a Buffy Halloween extravaganza!"

Given that Noxon and co. plan to expand Dawn's circle of friends, Tamblyn's stint may well extend beyond the haunted holiday season. Exploring Dawn's world, says Noxon, "gives us an opportunity to do some of the stuff that we didn't get to with Sarah Michelle Gellar when Buffy was in high school."

Next up, Broadway biggie Hinton Battle — a Tony winner for Sophisticated Ladies and The Tap Dance — has been drafted to appear in the eagerly anticipated all-musical Buffy (airing Nov. 6). "He's playing a demon," Noxon confides.

Finally, years after her cheerleading enchantress character was turned into a rodent, Elizabeth Anne Allen is being given some more face time. "Amy the rat is coming back," Noxon admits, "as a person."

Alas, other former favorites are less likely to drop in. Now that Buffy again has a pulse, a visit with the heartthrob who always made it race — Riley — is a no-brainer. However, sighs Noxon, "that's a big, big maybe. It depends on if Marc Blucas is available. He's turning into a big, fancy movie guy.

"Between him and Seth Green [who played Willow's beau, Oz], we're stuck," she adds. "And forget about Eliza Dushku [aka rogue Slayer Faith] — we can't get her back."