Sam Witwer by Michael Courtney/The CW Sam Witwer by Michael Courtney/The CW

Over the past seven seasons, Smallville's Hunk of Steel Clark Kent has toiled with friends and foes from the DC Comics pantheon. In the September 25 episode, Clark ( Tom Welling) has his first meeting with a character who could fit into both categories: the one and only Doomsday. Just don't call him that to his face. "It's an interpretation of the character," explains Battlestar Galactica vet Sam Witwer, the actor playing Davis Bloome, a Metropolis paramedic with the worst split personality this side of Jekyll and Hyde. "Contrary to popular belief, we're not trashing the Doomsday backstory that he's this [alien] experiment from Krypton we're adding to it."

In fact, the story has DC's blessing. "We always work with them really closely," says exec producer Kelly Souders. "They were very much in support of Smallville giving a new spin on his origin story. But eventually it does link up with what people know from the comics."

Introduced as a fast friend of Chloe ( Allison Mack), Bloome could be the boy most likely to steal Miss Sullivan's heart. "He's a really nice guy," Witwer says. "But she's dating Jimmy Olsen ( Aaron Ashmore), so Davis doesn't mess with that." Especially since he's got bigger things to worry about. "He realizes he's missing large chunks of time, so he embarks on a journey to figure out what happens when he's blacking out." What Bloome finds will not only be "horrifying," it may also trigger a battle royale with our hero-in-training.

"Remember, Doomsday is the only character who ever killed Superman," says Witwer, referring to the 1992 comic-book story line "The Death of Superman," which saw the last son of Krypton dying from his injuries after an epic face-off with the monster. Of course, Witwer won't say how deadly Davis becomes, but he assures us that "this story may be the darkest thing they've ever done on Smallville."

Not that Witwer has a problem with the dark side. Before landing on Smallville, the Juilliard-trained Illinois native portrayed Darth Vader's Secret Apprentice in the just-released video game Star Wars: The Force Unleashed. "As a Star Wars fan, it's unbelievable," he says. "It tells a very key part of what happens after Episode III and just before Episode IV."

It sounds like Witwer is in for a Vader-like evolution on Smallville, as he fills in the villainous void left by Michael Rosenbaum's MIA Lex Luthor. (The actor left the show after last season but might return for a guest appearance.) "This season is very much about identities," Souders says. "As Clark's double identity begins to emerge, so does Davis', and the unfortunate thing is that, although Clark is emerging as a greater hero, Davis is [becoming] a villainso this is a good person trying to reconcile his evil fate." - Damian Holbrook

Smallville's cast dishes on the news season:
" Allison Mack
" Justin Hartley
" Sam Witwer (aka Davis Bloome/Doomsday)
" Writers Kelly Souders and Brian Peterson
" Cassidy Freedman