All season long on CBS' CSI (Thursdays at 9 pm/ET), it's been the little things that have given Gil Grissom (William Petersen) the biggest headaches. Literally. He's spent the year hunting down a killer who creates exact miniature replicas of crime scenes — and even took a sabbatical to escape the stress. But now it looks like his search for the psychopath will pay off. "The killer will definitely be revealed," says executive producer Naren Shankar. "This is going to be a disturbing and very, very creepy episode."

All of the CSI team will be involved in the hunt to find the killer and save the next victim, but it's going to be Grissom doing most of the work. In fact, he's become so obsessed with the case, he takes to building his own miniature that Shankar says will play a key role in the finale episode. "This really has been Grissom's season-long story line, so the finale will focus on him. But what happens is not going to leave him the same as he was when we first saw him this year."

Way back then, viewers were just coming to terms with his secret relationship with Sara Sidle (Jorja Fox). And in the finale, according to Shankar, "this is the episode where Grissom goes public with the relationship" after Sara suddenly disappears. Fox's contract with the show is up at the end of this season (see related TV Guide News Report), and the network has no comment on whether she'll be returning next season. Shankar will only admit that the situation Sara finds herself in "will have some significant ramifications for her relationship with Grissom."

CSI producers dreamed up all these plot twists a year ago, and while they are pleased the miniature-killer story line has played out exactly as they'd hoped it would, there may be more to it than even they had first imagined. Grissom and his investigators will be discovering who the killer is, but there are more surprises in store.

Remember last May when Nick Stokes (George Eads) was buried alive in the '05 finale and the Grissom-Sara affair was revealed? Well, shockers from this week's big finish will carry over to next season, too. Explains Shankar, "We have no intention of tightly serializing the show, but we have tried over the past several years to pull character elements through so it's not like we're hitting the reset button at the start of every year. The end won't necessarily be the end."

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See the May 21 issue of TV Guide for a roundup of next week's prime-time cliff-hangers. Try four risk-free issues now!

It's taken all season, but Clark Kent is just about done rounding up all the prisoners he accidentally let escape from the Phantom Zone last fall. In tonight's Smallville season finale (8 pm/ET on the CW) he goes after the final fugitive. "The last Zoner is definitely trickier than the others, and will lead us into Season 7," previews executive producer Al Gough. "This won't be the last we hear from the Phantom Zone." It's not all bleak for Clarkie, though, as Lana (Kristin Kreuk) will be back on the market soon. Mrs. Luthor is going after Lex (Michael Rosenbaum) now that she knows he faked her pregnancy to manipulate her into marrying him. "She and Lex are way beyond marriage counseling," Gough says. "Now Lex is gonna find out what Lana's been up to. These two make Ike and Tina look like domestic bliss." The action-packed hour will also finally reveal the Kryptonite-fueled ability that's been lying dormant in Clark's pal Chloe (Allison Mack). Gough won't say what her superpower is, but advises to keep an eye on Lois Lane (Erica Durance) in the episode. Lois has a "very important" role, he says, and "she is the key to Chloe's power manifesting."And what would a Smallville season finale be without an explosive ending? Gough will neither confirm nor deny the rumor that a series star — Clark, Lana, Lex or Chloe — is going to die, and only offers up this tease: "Who says only one character can die in a finale?"

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