There is an explosion at Luthorcorp when Oliver is about to announce he controls the interests of Luthorcorp. Oliver suspects Lex is behind the explosion but he realizes the bomb was made by an ex Queen Industries' employee called Winslow Schott. Lana learns her power suit gives her the power to absorb Kryptonite.
Oliver Queen shows up at a Luthor Corp. board meeting with some mind-blowing news, but that's nothing, compared to what awaits him in the board room, and ends up asking Chloe to lie to Clark. Lana, now an equal to Clark in his powers, asks to share his secret life with her, as well.
When Oliver announces to the LutherCorp board Queen Industries has achieve a controlling interest, he alone can duck in time to avoid being killed by an exploding office toy. In hospital, he tells Chloe to suspect fired toy development genius Winslow Schott, as an agent of Lex, the brains behind a bombs terror wave. She promises to keep silent, but Clark drags it out of her. Meanwhile Winslow brings an explosive toy-monkey to execute Oliver, who manages to overpower him and sets out bent on revenge on Lex. Clark wants to prevent any murder, Chloe must admit mixed feelings.
- A toymaker is having a conversation with a ventriloquist's dummy about the joy of toys.
Meanwhile at the LuthorCorp Plaza, a meeting of the LuthorCorp Board of Directors is occurring. They are discussing the way Tess Mercer is running the company. Oliver Queen arrives unexpectedly and states that with Tess Mercer's assistance, he has purchased controlling interests in LuthorCorp, to the dismay of the Board. Oliver suddenly spots a Newton's cradle which has begun to swing back and forth and its movement is increasingly rapid. As he dives for cover, he shouts for everyone to get down, and the bomb explodes.
Clark and Lana are in bed discussing how they've always wanted to be together and now they finally can. Clark wants to do romantic things together but Lana asks him to take her patrolling. Chloe arrives and tells them about the explosion and that everyone but Oliver was killed, and he has been hospitalized.
Oliver is in the hospital pondering his situation when Lana and Clark speed into the room and ask what happened. Suspicions arise that Lex was behind the attack, and Clark and Lana promise to investigate.
Clark and Lana arrive at the crime scene and discover kryptonite embedded in a chip made by Queen Industries, Clark is visibly weakened and when Lana handles it the kryptonite loses its power. Lana thinks that Oliver is trying to kill Lex, and Clark agrees that he can't be trusted.
Oliver is in the hospital flirting with his nurse when Chloe Sullivan arrives. Oliver tells her that he suspects Winslow Schott, a former Queen Industries employee, of being behind the bomb: Schott was fired when he became psychotic and Oliver thinks he has now been hired by Lex to kill him. He asks Chloe to track him down because he probably knows Lex's location. Chloe is hesitant and wants to tell Clark, but Oliver tells her not to because Clark won't agree to killing Lex.
Clark arrives to see Oliver on his jet, only to find Chloe, who is searching for clues as to where Winslow may be. Chloe doesn't want to tell Clark where Schott is because Lex knows Clark's weakness and she thinks he will be in danger. They have a tense conversation in which Clark finally gets her to admit that she is helping Ollie track down Lex. Clark wonders if she is helping Oliver kill Lex because he himself won't do it. Chloe doesn't answer and Clark reminds her that he could have killed her when she was infected by Brainiac, in order to save others, but he didn't, and she shouldn't let Oliver have the right either. Chloe relents and shows him what she has found about Winslow.
Clark and Lana are at the farm trying to locate Winslow, but they cannot find him. Lana finds her necklace and Clark puts it back on her. She explains that Dr. Groll told her that she absorbed the kryptonite radiation from the bomb at Luthercorp and wonders if Lex was indeed behind the bomb. Winslow is in the hospital delivering "balloons and presents" to Oliver. He chains Oliver to his bed and states that Oliver will pay for the way he treated Schott when he was ill. Oliver tries to sarcastically dismiss him but it doesn't work and Winslow states he is working for Lex for vengeance. He activates a toy monkey which will bang its cymbal 53 times - the same number as the number of patents he registered for Queen Industries - and it will then detonate. Oliver manages to free himself and extort the information from Winslow and he disarms the bomb. He ties Winslow to the hospital bed.
Chloe goes to talk to Oliver but only finds Winslow, being freed by an unsuspecting nurse. Before she can stop him, Winslow pops the balloons he's delivered, filling the room with a gas that knocks Chloe and the nurse unconscious.
Clark picks Chloe up from the hospital and takes her back to the Isis Foundation. She helps him locate Winslow's hiding spot and makes him a device so they can track Lex down as well.
Clark and Lana arrive at the place, an abandoned warehouse filled with toys and a replica city of Metropolis showing the Daily Planet building in ruins. Now knowing that the Planet is the next target, they head there and find a bomb made entirely out of kryptonite on the roof.
Lex watches this and speaks to them, saying that they are the reason he lost everything, Lana has to make a choice between Clark and the people of Metropolis. If Lana absorbs the kryptonite radiation, the city will be saved, but Clark can never come near Lana again. After one last kiss with Clark, Lana absorbs all of the kryptonite radiation and deactivates the bomb.
Clark uses Chloe's GPS device to locate Lex. It takes him to a truck with Lex presumably inside. He declares that Lex will never hurt anyone ever again but as he approaches the truck in a rage, Lana speeds in front of him. As she tells him that killing Lex would cause Clark to lose not just her, but himself as well, Clark looks on in shock as the truck holding Lex explodes.
Chloe reviews security footage of the hospital and sees Oliver leave with Winslow's toy monkey bomb, realizing that Oliver blew up the truck. Oliver arrives and Chloe confronts him, revealing that the remains in the truck were identified as Lex. He responds by telling her he knows she killed Sebastian Kane. Chloe claims Brainiac killed Sebastian Kane, but Oliver presses by asking her if she was truly sorry Lex is dead. Chloe admits that she is not. Oliver asks her not to tell Clark of the true reason why Lex died.
Clark revisits the exploded truck in which Lex died and spreads a handful of ashes.
Oliver contemplates a ripped-up photograph of Lex and holds his kryptonite ring.
Chloe and Lana wordlessly hug in the Talon apartment.
Clark meets Lana in the loft and she explains that Dr. Groll has told her that he is unable to reverse what has happened to her. Clark cannot approach Lana without becoming sick. She tells him that she is driven to use her powers to preserve life. Clark asks her to stay. She says she is not strong enough to be around him but not be with him. Clark suffers through the radiation sickness to kiss her one last time until he falls to his knees from the pain. Lana leaves in tears.