Season synopsis
Contains spoilers for this season and earlier seasons.
Clark returns to Smallville after three months missing, but the Kryptonian identity Kal-El has taken control and is searching for three knowledge crystals. Lois Lane arrives to investigate Chloe Sullivan’s presumed murder, and her questions draw her into the Kents’ lives. Lana comes home from Paris with a mysterious mark linked to the caves and becomes possessed by Isobel, a witch whose search for the crystals entangles Lana, Chloe and Lois. Clark and Lana’s new boyfriend Jason pursue the stones across Smallville and as far as China, while Lex follows his own trail. Their struggle brings Clark closer to Jor-El’s plans for him and exposes how much the crystals can endanger the people around him.
Alicia Baker engineers Chloe’s discovery of Clark’s powers, and Chloe keeps what she has learned private through the end of the season. Clark and Chloe later investigate Alicia’s murder and the forces surrounding the Teagues, while Jason and his mother Genevieve keep pressing the search for the stones. At Smallville High, Clark, Lana and Chloe approach graduation with the crystal hunt unresolved. Isobel kills Genevieve with one of the stones, ending her hold over Lana and triggering a second meteor shower. As the graduating class evacuates and meteorites strike Smallville, Clark gathers the three crystals; Chloe stays behind and helps him against Lex’s interference, and their union transports Clark to the Arctic.