What's up with Lana: Lana goes to see Clark. She tells him she's worried about Jason and wants him to protect her. She professes her love for Clark and the two kiss. Before they can round first, Jason shows up and throws Clark off Lana. He knocks him out and proclaims no one can protect her from him. Turns out Lana doesn't need protecting, she punches him in the stomach and he falls out of the barn... but when he lands, he lands on a table at the Talon. Lana comes down from her apartment upstairs, concerned for Jason's safety.

What's up with Jason: As Jason lies in a hospital bed with Lana by his side, Clark and Chloe show up to see what's wrong. Lana tells them what happened, that Jason came by the Talon to pick her up and next thing she knew he was out cold. The doctors don't know what's wrong, just that his heart rate and blood pressure are sky high, even thou he's in a coma. He appears to be having a severe nightmare, and if they can't get his heart rate down, he may die.

What's up with Chloe: Chloe and Clark go to Lana's to pick up Jason's insurance card. While there Chloe decides to do some investigating to see what Jason's been up to, maybe there's clues there that might help. They find out he had a meeting at Luthorcorp that morning. When they get to Luthorcorp, it's deserted. Clark finds Lex, who seems preoccupied and annoyed Clark's there. He agrees to help anyway, Jason was there looking for work. While they talk, Chloe snoops around on her own. She ends up seeing her mom in a dimly lit room. It's a terrible nightmare and Clark finds her violently sleep walking in the plant.

What's up with Lex: Luthorcorp was creating a toxic bacteria for the military that produced extreme nightmares for those exposed. Meteor rocks were involved and the lab exploded. Lex is upset and takes full responsibility for his infected men. When the antidote is done, he goes in with the doctor to treat the sickest of his men. The antidote is unsuccessful and the worker dies, but not before he rips Lex's suit, exposing him to the toxin.

What's up with Lionel: The appellate court has overturned his conviction. The warden tells him, but Lionel isn't excited. He says he's found his mission in life, helping those in prison. Besides, he's guilty of so many wrongs. The warden shakes her head, it's not his choice, like it or not, he's a free man.

What's up with Clark: More people are coming down with the sickness and one person dies. Lana can't sit by while Jason and Chloe die, so she tells Clark she wants to help. They investigate and find out that there was a leak at the plant, hundreds could be infected. Just then, Lana slips into a nightmare state. She dreams she's in a morgue with her dead parents, and a dead Jason.

How it ends up: Lex goes to the hospital and tells the doctors what he knows. Clark brings in Lana and as he's arguing with Lex, he falls victim to the toxin. In his nightmare, Lana finds out he's an alien and blames him for her parents death. Just as Lana is about to plunge a stick of kryptonite into Clark, he wakes up! He runs to Luthorcorp and tells Lex to use his blood to save others. Lex looks intrigued but tells him they already have another antidote on its way. It just has to super heat. As Lex and his doctor argue about who they'll test the antidote on, Clark super heats it and it's ready. Lex grabs it and the doctor sarcastically asks who he'll kill next. Before Clark or the doctor can stop him, Lex turns the needle on himself.

In his nightmare, Lex is the President of the United States. He launches a nuclear attack and the world ends. Luckily, Lex's world doesn't end. The antidote is a success. Lex and the others are saved.

Meanwhile, Lionel is released from prison. When he's free he gets in a limo and is happy to see the person who set him free.

Lana goes to see Jason, who's packing up. He says he doesn't like who he's becoming and that's why he's leaving. Lana doesn't buy it and asks for the truth. He kisses her goodbye, tells her to be careful, and walks out of her life.

Chloe and Clark share a moment in the Torch's office. She tells him she really did find her mom three months ago and that she's in a mental institution. The kicker is, it's hereditary. Clark is there for her and she feels much better for telling her secret, much less alone. Unfortunately Clark can't seem to muster the same courage.

TOXIC WASTE - Lex's secret experiment at Luthorcorp goes awry and causes a dangerous toxin to be released into Smallville. Those infected by the toxin, including Clark, Lana, Lex, and Jason imagine their greatest fears come true and then fall into a coma. Desperate to find a cure, Clark gives some of his blood to Lex and is stunned at what Lex does with the antidote.
Allison Mack, John Glover, Annette O'Toole and John Schneider also star.
David Carson directed the episode written by Kelly Souders and Brian Peterson.

Have you ever smelled a fart so bad that it made your nightmares come to life? If your nightmare is smelling a really bad fart, then it could happen to you all the time. In the Smallville version, though, it's more of a toxic gas emanating from Lex's assets (LuthorCorp, to be exact), which infects a good chunk of the town, starting with Jason, who dreams that Lana gets her red stiletto-heeled groove on with Clark and then stabs Jason in the stomach. O, metaphor! Jason ends up in a coma, as does everybody else infected, with his heart racing in a panic that threatens to send him into cardiac arrest. Chloe and Clark try to figure out what's up, and quickly backtrack Jason's day to Lex, whose company was offering Jason a job that Lana didn't know about. Chloe catches nightmare fever too, as does Lana, and soon Lex himself has a rehash of his White House vision (or rather Cassandra's vision) from "Hourglass." Clark is semi-immune to the toxin (he has a nightmare, but comes out of his coma), but it doesn't really matter, because Lex's team develops an antidote that saves the town. Jason wakes up and figures out what we've known all along: he's a putz when he's with Lana, and he needs to get the hell out of Dodge. Clark decides he really really doesn't want to tell Lana his secret. Papa Luthor gets a Get Out of Prison Free card and, despite his benevolent protests, ends up using it. And Chloe drops two bombshells: she's tracked down her long-missing mother, who is in a mental asylum. And her mom's mental illness is hereditary. Plus: she knows Clark's secret. But no pressure, Clark. You can tell her whenever you like. Just please do it before she gets killed off or something, all right?

Lana shows up at Clark's loft and asks for help – she believes Jason is lying to him. She then admits she shouldn't have given up on the two of them and they start to kiss. Then Jason barges in and beats up Clark, knocking him out. Then Lana stabs Jason . . . and he falls off the balcony at the Talon.

Jason is in a coma at the hospital with his heart in bad condition. Chloe and Clark check up and find Jason had a meeting at LuthorCorp to get a job. They go visiting and Clark meets up with Lex, who is angry he's in a restricted area and claims he didn't meet with Jason himself. Chloe goes off on her own and when there's a power failure she finds a spooky basement area and a woman – Chloe's mom. The woman warns that Chloe can't escape – none of the women in their family have. It becomes clear Chloe is hallucinating as Clark and a security guard find her. Clark knocks out the guard and he gets her out.

At a lab within the facility, Lex is meeting with a team that was working on an experiment with meteor rocks and unconscious subjects. A bacteria is leaking out and Lex orders the project (contracted with the military) dismantled. The head guy, Dr. Ford, is working on an antidote and confirms the bacteria is only transmitted through inhalation. Clark finds out other folks not at LuthorCorp are suffering the same symptoms and one has died. At the prison the warden reveals Lionel's sentence has been overturned by a mysterious someone and he can be freed but he chooses to remain in the prison and "do good."

Checking weather patterns, Clark and Lana find the presence of a mysterious "cloud" and Lana is infected – she hallucinates being in a room with the dead bodies of her mother and father and her friends, and a corpse warning her everyone will leave her. Dr. Ford comes up with an antidote but it contains elements of the bacteria – Lex takes the responsibility and goes in to administer the antidote. It kills a patient but not before he rips Lex's suit.

Lex goes to the hospital and finds out how far spread the infection is. He reveals the nature of the "disease" while Clark arrives with Lana. Then a series of explosions rock the hospital – in reality, Clark hallucinates a new meteor shower that bombards him with kryptonite and exposes his powers to Lana. Dream-Lana "kills" him . . . and Clark wakes up, cured. He goes to his parents who have collapsed, then confronts Lex. Clark realizes his blood may be the cure since he's immune but Lex wants to wait for the current antidote to heat to the proper temperature. Clark secretly superheats the antidote and Lex takes the serum himself. Lex begins hallucinating back to his future vision of himself as President launching nuclear missiles and destroying the world, but snaps out of it.

Clark and his parents return to the farm and discuss things – Clark realizes he can't reveal his secret to anyone. Jason is considering leaving since he doesn't like what he's becoming – Lana senses he has a secret but he leaves rather then reveal it. Chloe and Clark talk about Chloe's anxiety over her mother and reveals she knew about her mother for three months – her mom is in a mental institution with a hereditary disease. Clark is forced to dodge on telling his own secret fear.

Back at the penitentiary, Lionel leaves the prison and is greeted by his benefactor . . . who he knows.

Chloe: Clark, you were in love with her. That's not something you ease out of.

[During Chloe's nightmare]
Chloe's mom: You can't escape this Chloe. None of the woman in our family ever have.

Lana (to The Kents): I can't just sit in that hospital anymore, just watching Chloe and Jason die. I want to help.

Warden Stone: You want to stay in prison?
Lionel: Yes. I've found my mission in life.

Lionel But who? Who could do that?
Warden Stone: Obviously someone more powerful than you.

[During Lana's nightmare]
Lana (to herself): Lana... Lana... they're all going to leave you and there's nothing you can do about it.

[During Clark's nightmare]
Lana (to Clark): It all makes since. The meteor shower. That's the day you came. How could I be so stupid?... My parents are gone because of you. I'm never going to see them again... You killed my parents!

[On telling Lana his secret]
Clark (to Martha): As far apart as we've grown, I think about it everyday.

Jonathan (to Clark): Someday there will be someone you can tell.

Jason (to Lana): Six months ago I would've never gone to someone like Lex and groveled for a job I don't even want.

Lana (to Jason): The one thing I've learned from my relationship with Clark is when someone isn't being honest with me.

Chloe (to Clark): It turns out she is not exactly M.I.A. so to speak. She's in a mental facility and the kicker is it's hereditary.

Clark (to Chloe): It's weird when people think they are so close to you when they have no idea what you're really going through.

Chloe (to Clark): I mean if you can't tell your best friend, who can you tell? Right, Clark?

Song: "Falling"
Artist: Mindy Smith
Album: One Moment More

Nightmares:
Jason: After becoming a stalker and a door mat to Lana, she betrays him in order to be with Clark.

Chloe: Her mother tells her she will end up in a mental institution like all of the other women in their family.

Lana: After finding her mom, dad, Jason and Chloe dead, Lana realizes she will always be alone.

Clark: Lana discovers his secret after a meteor shower and blames Clark for the death of her parents.

Lex: As president, he is responsible for the end of the world.

Malcolm Stewart (Dr. Otis Ford) previously played Mr. Wilson (Jodi's Dad), in the first season episode "Craving".

Footage from the first season episode "Hourglass" was used.

Neither Clark nor Lex appeared in Laa.s nightmare as people she loved.

Hallicinations:
Chloe sees a woman she thinks is her mother, in a straight jacket. "I've been waiting for you, Chloe," the woman says. "You can't escape it. No women in our family ever have." The woman turns around, and her face is revealed as a gaunt version of Chloe herself!

Lex sees himself at a church. A priest asks if he and a veiled woman are to be lawfully wedded husband and wife. The veiled woman is... Lana! "No!" she exclaims. "I could never love you, Lex."

Jason has a meeting at LuthorCorp to meet with Human Resources. It looks like people know about Lana and Jason. Lionel, still in prison, plays chess with another inmate. Lionel claims that he's a changed man and wants to help his fellowmen, his cellmates, and that he wants to stay in prison! Chloe and Clark go on a secret field trip at LuthorCorp where things are too quiet compared to usual. An accident involving the meteor rocks happened at LuthorCorp and several employees are unconcious. The infected personnel are quarantined and the other employees are trying to fix the leak. They were working on a military project to create a toxin that would invoke people's worst nightmares so that the Army could disable the enemy without using force... but someone who visited the plant is now in the hospital could it spread? Will they find the antidote in time because the human body cannot withstand that amount of fear for very long.