Craig Veroni

Clark discovers the reason he was sent to Earth after a nightmare foretells a horrible event that's about to befall Smallville, and he visits the cave to seek answers from Jor-El. His biological father tells Clark he must reunite the three crystals immediately or an enormous disaster will devastate the planet that even Clark won't be able to stop or survive. Meanwhile, after finding Lana with Genevieve Teague's dead body, Lex helps the teen escape Smallville then takes shocking action to get one of the crystals away from Lionel. Realizing the elements are connected to Clark, Chloe tries to stop Lex from discovering the truth.

Martha is seriously sickened by meteor dust, and Clark and Jonathan desperately try to help her. But when Clark becomes infected as well, he finds out just how vulnerable he can be. Only a miracle can save Clark and his mother--and the amazing secret she holds within. Meanwhile, Lex confronts his feelings for Helen (recurring guest star EMMANUELLE VAUGIER) as she considers an enticing out-of-town research position. And Chloe and Lana cope with the unthinkable possibility that they may lose Clark forever.