Smallville: Season 4, Episode 15

4 - 15: Sacred

After learning that Jason and Lex are in China searching for one of the mysterious kryptonian crystals, Clark and Lana follow in the hopes of finding it first. Clark finds an artifact that leads them to the crystal, but he must battle Isobel, the witch, who has once again inhabited Lana's body in order to take the crystal for herself. Meanwhile, Lex has more information on the crystals than he is letting on...