Michael Rosenbaum and Tom Welling, <EM>Smallville</EM> Michael Rosenbaum and Tom Welling, Smallville

Fans of WB's Smallville (Thursdays at 8 pm/ET) have long wondered when the friendship between Clark Kent and Lex Luthor would eventually crumble. The sizzling March 30 episode  "Hypnotic," the first new installment in six weeks  shows how the farm boy and the rich kid are evolving into the sworn enemies we recall from comic-book and screen lore.

Lex's clandestine attempts to discover Clark's secrets  and uncover the lies Clark has told to protect them  have been mounting over five seasons. Now, "there's just complete mistrust between the two of them," says Tom Welling, who plays Clark.

The animosity intensifies this week when a sultry young woman named Simone hits town and puts Clark under her supernatural spell. "You find out that it's a scheme of Lex's to not only try to find out about Clark, but also to break up Lana and Clark," says executive producer Al Gough. In an ironic twist, because Lex (Michael Rosenbaum) is blackmailing Simone about a crime she committed, she hypnotizes Clark and sends him out to kill Lex!

Meanwhile, the Teen of Steel's once-idyllic relationship with Lana (Kristin Kreuk) has grown hopelessly strained. Clark's fears that she would not be able to accept his alien roots have been replaced by worries that Lana's life would be jeopardized by getting too close to him. (It's taken quite literally: Clark suspects supersex could be fatal to Lana.)

The result of Simone's spell, though indirect, is inarguable. "It leads Clark to finally do the heroic thing and break it off with Lana, because it isn't going to work [between them]," says Gough. And Ms. Lang's reaction? "She doesn't take it lying down. No, you're going to see Lana slightly unleashed as well. You know the old saying, 'Hell hath no fury....'"

Will rejection send Lana into Lex's arms? "You'll definitely see them getting closer toward the end of the season," Gough previews. "For that reason, Lex is being very open and honest with her, and after Clark, she finds that refreshing.

"Look, he's rich and he's sexy and there's always been an attraction between Lex and Lana," says Gough. "Whether or not she wants to admit it, Lana has always had some feelings for Lex."

Were the Smallville torment only limited to just this twisted triangle. Rather, the imminent return of James Marsters' Milton Fine (aka Brainiac) promises only more speed bumps for he who is faster than... you know. "Fine resurfaces in Honduras, and when Lex, who has been searching for him, finally comes across him, the question is, Who's playing who?" Gough teases. "Did Lex find him, or did Fine allow himself to be found?"

Whatever the case, the eventual net result can't be good for Clark. "Fine's first plan to get Zod out of the Fortress failed, so Plan No. 2"  which won't be fully revealed to Smallville viewers until the season's final two episodes  "is much bigger, and with greater consequences."