A flower that comes from a reopened "Level Three" of the fertilizer plant brings strange reactions from several people, including Jonathan, Lana, and Pete.
A man from Lex's past stalks him in conjunction with a mysterious death at Club Zero that Lex may have been responsible for. Meanwhile Chloe looks into Clark's past as an adopted child.
Whitney falls in with some former jocks who have kryptonite tattoos that give them the power to walk through walls. Meanwhile, Chloe is seriously injured and Lex has his own plans.
On a class trip, Clark and a fellow student named Eric are struck by lightning, and because Eric was holding a piece of kryptonite, Clark's powers are transferred into him.