Jared Padalecki and Sandra McCoy, Supernatural

The Big Bad Wolf attacks Little Red Riding Hood. A murderous old lady in a cottage menaces a couple lost in the woods. A beautiful teenager is cruelly abused by her wicked stepmother. It's just another day on Supernatural (Thursdays, 9 pm/ET, CW).

In keeping with the show's dark mythology, when these familiar fairy tales surface in the Nov. 1 episode, "Bedtime Stories," it's no Disney cartoon. These twisted fables are grim. Brothers Grimm, to be exact. "When I went back and read the original stories, they were creepy and freaky," says Jared Padalecki, who plays Sam, the younger of the two demon-hunting Winchester brothers. "I was actually a little spooked. I grew up on the Disney movies, and I'm going, 'Oh, my god, this is what it came from?'"

That reaction pleases executive pro­ducer Eric Kripke. "The Grimm Brothers' fairy tales are coming to life in all their bloody, homicidal, cannibalistic glory. The monsters and ghosts the boys are up against are always based on folklore or modern urban legends, and we realized that the folklore most people know best had never been on the show: fairy tales."

Sam and his brother, Dean (Jensen Ackles), arrive in the fictional town of Maple Springs to investigate what seems to be a savage werewolf attack on three chubby construction foremen (think the Three Little Pigs). As the crimes continue, the boys discover an ethereal young girl with pale skin and dark hair who's watching each gruesome bloodletting with an eerie calm. "We need to figure out which fairy tales are about to come true, where they'll come true and how we will hope­fully stop it," Padalecki explains.

That's not all Sam is trying to stop. In a continuing storyline, he's searching for a way to break the bargain his older brother made with the Crossroads Demon. Dean agreed to go to Hell in one year in exchange for Sam's being brought back from the dead. But is the resurrected Sam the real Sam? Or is he, as some who know him suspect, an überdemon?

"Keep an eye on him and notice the difference between Season 1 and what he does now, and it might be hinting to­ward something," reveals Padalecki, who admits he had a particularly good time with this incarnation of the Crossroads Demon. The shape-shifter is played by his real-life girlfriend, Sandra McCoy. (They met while making the horror flick Cry Wolf three years ago.) "The producers have been trying to find a role for her for a while. She was awesome."

By the episode's end, Sam makes a shock­ing discovery. Without spoiling too much, it's safe to say Dean's situation will get worse before it gets better. "I'm getting more and more nervous with each script," Ackles says. "Please write to Kripke. Tell him not to kill me."

You can watch more of Supernatural's bloody tales in our Online Video Guide.

Get an exclusive sneak peek at the CSI/Without a Trace crossover event in the Oct. 29 issue of TV Guide. Plus: The truth behind Oprah's health scare. Try four risk-free issues now!

Send your comments on this Q&A to letters@tvguide.com.