Death and destruction have always been hallmarks of Smallville season finales, but this year’s closer titled “Doomsday”—might set a new standard for bloodshed. The season-long evolution of paramedic Davis Bloome (Sam Witwer) into the full-fledged killing beast Doomsday climaxes this week when Clark (Tom Welling) struggles to stop his fellow Kryptonian—without killing him, or getting himself killed.

As comic fans know, Doomsday and Superman battled to the death in a famous 1992-93 storyline. “When we created our version of Doomsday, it was important that he be linked up with DC Comics mythology,” says executive producer Kelly Souders. “I don’t think fans will be disappointed. He really becomes the Doomsday that people know from the comics.”

Complicating matters for Clark is that he’s on the outs with his super friends. His ongoing debate with Oliver/Green Arrow (Justin Hartley) over whether or not killing can ever be justified came to a head last week when Ollie admitted to killing Lex. Fellow Justice Leaguers Impulse (Kyle Gallner) and Black Canary (Alaina Huffman) step in to try taking down Davis, while Legion leader Rokk (Ryan Kennedy) travels back from the 31st Century to give Clark a prophetic warning.

Caught in the middle of the Clark/Davis drama is Chloe (Allison Mack), who has had, to put it mildly, a rough year. She’s been possessed by Brainiac, seen her wedding to Jimmy (Aaron Ashmore) violently crashed by Doomsday, and then subsequently come to Davis’ rescue, helping him avoid capture. That has lead to the end of her marriage, and a major strain on her friendship with Clark. She seems to want to help both Davis and Clark, goals that appear unlikely to synch up. And apparently it’s not going to get any better in the finale. “Chloe has the most traumatic end to a rather traumatic season,” Souders warns. “That character has really been put through the wringer this season and been torn and conflicted, and unfortunately those issues are not going to go away in the finale.”

As for Chloe’s estranged husband, Souders says, “the one thing that’s been great about Jimmy is that he’s battled some demons this season, but the heroic side of Jimmy really comes to fruition in the finale.”

And as if the episode doesn’t seem crowded enough, Souders teases that “somebody new and old is going to show up.” This familiar face is likely to be back for Season 9. Given last week’s out-of-nowhere kicker that the lost Kryptonian city of Kandor apparently survived the planet's destruction and must be saved, our guess is cousin Kara (Laura Vandervoort), who was last seen in the fall, going off on a journey to find Kandor. Whatever the outcome, Souders says the Smallville writing team is already eager to start mapping Season 9. “The finale shakes a lot of things up,” she says. “It’s a good push-off for next year. Clark’s decisions in the finale force him on a path that he wasn’t expecting.”

The season finale of Smallville airs Thursday, May 14, 8/7c, The CW.