Chloe and Jimmy are out at the local necking spot at Jimmy’s insistence of checking out something weird. They briefly discuss their relationship and how they should take it slow, then start kissing. They’re interrupted when they hear a scream from a couple that ran off to skinny dip. They go to investigate and find their clothing, and then drops of blood falling from the tree above them from the woman’s corpse, impaled on the branches.

Martha receives an invitation to the “Dark Thursday” ball Lex is throwing. She asks Clark about whether he’s over Lana and Lex being together, and he says he’s okay.

Lex is preparing for the ball when Lana comes in, unhappy with her picture in the paper as a “Lex girl.” Lana wonders whether she’ll be another notch on Lex’s bed post, and in return he says he doesn’t want her issues with Clark to interfere with her relationship with him.

Clark visits Chloe who tells him what she found and how the guy disappeared. She wonders if the guy is a krypto-mutant and Clark wonders what she was doing there, as Jimmy comes in.

Lois is at the Kents looking for job opportunities at the Inquisitor when Oliver Queen arrives to deliver a letter from his company. Lois thinks he’s the courier and sends him off, and Martha comes down and tells her who Oliver really is. Since she was counting on Oliver’s support, she’s not happy.

Clark and Chloe go out to the woods where the search parties are looking for the boy, and Clark gets to the crime scene where a ranger, Gloria, confronts him. They chat and Gloria thinks she recognizes Clark. He scans the area and finds the boy, alive, buried in some woods. Clark tries to get him free and cuts his hands on the thorns.

At the hospital, the boy is in ICU and Chloe, Clark, and Jimmy sneak in to check him out. They find some x-rays that show he has something in his lungs. Jimmy is overly concerned about Chloe, which she finds flattering. After he leaves, Clark talks to Chloe about his suspicion that Lex is involved since the murder occurred near his estate. Clark goes to the estate’s greenhouse where he finds some suspicious seeds, and Lex confronts him. They spar over Lana and Lex tells Clark to leave.

Lana drops some of Chloe’s stuff off as an excuse to talk to her about her problems with Lex. In the woods, Jimmy checks out the murder scene when Gloria confronts him. She briefly comes on to him, then throws him to the ground and causes the plants to grab him and extend vines down his throat.

At his office/apartment in the clock tower, Oliver is practicing yoga when Lois arrives and tries to apologize without much luck. Oliver invites her to Lex’s ball and offers her a Maid Marian costume to wear.

Clark and Chloe are at the hospital as the boy undergoes surgery for removal. Chloe’s botanist friend has determined that the plant is alien in origin. They hear the doctors panic and find that the boy’s entire room is overgrown with vines that have grown out of his chest, killing him. The EMTs bring in the park ranger, but it’s not Gloria who Clark met earlier. They figure that Gloria is involved, and the plant needs male human bodies to breed so it killed the girl. As Clark leaves to confront Gloria, Chloe notices that the vines from the boy’s chest are easily electrocuted.

Clark confronts Gloria who claims she can’t go back to her home world because it was built over. Clark figures out she’s from the Phantom Zone and she came through with him. Clark suggests she adapt but she plans to use the ball to find more “suitors” to spread her glory. Gloria then impales Clark with her controlled vines and leaves, and he spots a cocooned Jimmy nearby before passing out.

At the charity ball, the All-American Regents are playing when Lex (dressed as Alexander the Great) arrives and is impressed when Lana arrives, dressed as Cleopatra, to be his date. Oliver (dressed as Robin Hood) arrives with Lois and he spars with Lex over their past relationship at boarding school. Lois introduces Oliver to Martha and he offers to consider her policy points.

Chloe goes out in the woods and finds Clark and Jimmy. She uses a taser to kill the vines and free Clark. She helps Jimmy while he goes to the greenhouse where Gloria is seducing one of the guests. Clark sends him packing, and then Gloria attacks him, animating the vines. Clark uses his heat vision to activate the sprinkler and electrify the plants as well as Gloria, killing them all.

Chloe gets the EMTs to get Jimmy and then uses a defib unit to kill the spores in his chest. After the party, Lois challenges Oliver to make a shot in return for a kiss and he apparently fluffs the shot--she leaves, unaware he shot the tab off.

After the party, Lex tells Lana he’s satisfied and they embrace. At the end, Clark is alone in his barn.