Allison and Carter are jogging together. Allison mentions she has no hot water at her house, and can't find a decent plumber. Carter volunteers to fix her water heater. When they get to her place, Stark is there installing a music therapy device for Kevin. He brags that Allison's water heater is a fusion water heater, and you need a PhD from MIT to even look at it... which he (Stark) happens to have.
While Carter is jogging home, he finds Fargo chasing and chastising his dog Sparky. Sparky runs out into the street, into the path of a semi. Fargo runs after the dog, and Carter runs after them both, to push Fargo out of the way of the truck, which swerves and crashes, spilling its liquid cargo. The driver is out of it, but alive. Fargo notices the semi's tank bears a "Toxic" warning. Carter mutters, "uh-oh".
Soon, a Hazmat team has arrived to decontaminate the area, and the victims. Carter's being decontaminated right on the green in a portable shower stall. Stark makes him take off his clothes. It's not pleasant. Carter goes home. Zoe asks him what happened. Carter replies, "I tempted fate." He tries to order up a beer but SARAH tells him alcohol isn't the answer.
In the next scene, Carter walks in to work-naked. He tells Jo, "damn! We're out fresh ground Vince-spresso!" and walks off to Café Diem, still naked. Allison sees him, drops her coffee, and asks him what he's doing. He says, "oh damn, not again," and wakes up. He hasn't had that dream since college.
Carter comes down to breakfast, and Zoe seems out of sorts. She mentions she had a weird nightmare and leaves in a hurry. At the office, Jo can't keep a straight face. She tells him she had the same exact dream about Carter being naked. They walk together to Café Diem, as they really are out of coffee, and discuss what could make them have the same dream. Dr. Childress, an efficiency expert, is lurking around, helping Vince to be more productive. Carter asks how she became an efficiency expert. She says the efficiency thing is just a hobby; she's actually a neurologist at Global who specializes in helping people to maximize cognitive potential. Vince tells Carter he ought to seek her help in that area. Carter is affronted (but used to this sort of abuse). Vince runs off to get Carter's coffee. Jo gets a call-the driver's awake and Allison wants to see them. Jo and Carter head off to GD to meet with Allison.
At GD, Allison tells them whenever there's an accident in Eureka with hazardous waste, they have to make sure it wasn't sabotage. Carter wants to know why anyone would mess with a shipment of toxic garbage. Allison tells him that's his job.
At the hospital, a hypochondriac Fargo is making a real pain of himself. They ask a nurse how the driver's doing. She tells them the driver will be fine but-sarcastically-Fargo may die. Carter asks Jake, the driver, if he remembers what happened. Jake is very cooperative and feels terrible about all this. Carter then asks him if he remembers his dreams from last night. Jake can't-but he is on some pretty ridiculous pain meds. Jo gets Jake's permission to search his house.
Stark is watching Kevin build his intricate replica of the artifact. Kevin tells Stark the thing is in his dreams. Allison enters, and Stark tells her that no matter what medium he gives Kevin, he makes the same thing, over and over again. Allison is worried about Kevin, but Stark tells her not to worry: they'll figure it out-very soon.
Jakes house is full of paintings. He's apparently an artist in addition to being a truck driver. Carter and Jo discuss dream jobs while they look around, and she tells him she wanted to be a dancer. Carter, gently mocking, calls her "Josefina ballerina." They find Jake's been moonlighting-doing deliveries for other companies. Maybe that made him tired and he fell asleep at the wheel.
At the hospital, Jake has a dream about the crash. Fargo, apparently sharing the dream, wakes up in time to find the hospital staff trying to resuscitate Jake, whose dream apparently killed him. They're unable to revive him, and he is pronounced dead.
Shortly after, Fargo tries to convince the nurses, Carter, and Henry that Jake died in real life because he died in the dream. The nurse has a strange look on her face, so Carter asks what she thinks. She tells him she had the exact same dream. The doctor pipes up that he did, too.
Jo and Carter talk to Allison at GD, telling her they think the contagious dreams are related to the toxic spill. Jo gets called away by another domestic dispute (these shared dreams are wreaking marital havoc, apparently). Allison is skeptical that dreams could be "contagious," but can't think of a better explanation. They go to see a scientist who is studying dreams, the aptly named Dr. Sueños, in a GD lab. Allison asks him if dying in death can cause dying in real life. The scientist would bet his life that it's not possible.
Allison has a dream that she's looking for Nathan and Kevin in Nathan's lab, but can't find them. Kevin pops up (talking and behaving like a normal boy) and says he's sorry she couldn't find him, but he has something he wants to show her. He opens a door, and reveals the artifact, alive again, glowing. Allison starts awake and kisses the sleeping Kevin on the forehead, whispering, "It worked, honey."
The sheriff's office has been flooded with people all arguing with each other. All these shared dreams are turning couples and coworkers and schoolmates all against each other. Carter and Jo call up Henry to see if the autopsy of Jake revealed anything. It didn't – Jake just plain stopped breathing. There are no drugs or toxins or anything that explains it.
Allison visits Nathan at his GD lab. She tells him gravely, "We have to stop. Other people are sharing dreams." Nathan scoffs, saying they'll be lucky if just Kevin and Allison get to share dreams – there's no way it would affect the whole town. Nathan reminds her that she had said she would give anything to be able to know what's going on inside Kevin, and he worked for months to try to give that to her. Allison acknowledges that it did work.
Carter examines the patterns of people who had shared dreams, and realizes that Café Diem seems exempt from the phenomenon. He asks Vincent for permission to let everyone sleep there. Vincent agrees.
Allison tells Nathan about the dream she shared with Kevin. Nathan explains what he thinks the artifact is: the antenna for the Akashic field – a zero-point energy field containing all the knowledge in the universe. He thinks that now Kevin is that antenna. Kevin was the only person exposed to the artifact whose "system didn't overload". Kevin's brain is uniquely wired. Allison asks what they are supposed to do now. Stark says "let Kevin show you what's in the vault."
Carter explains to the townspeople that they are performing an experiment to see whether it's the people or the places that were causing the shared dreams. They are all supposed to go to sleep and either not share dreams, or have the most horrifying shared dream experience ever. All the dream-sharers are packed into Café Diem pretty tightly. Dr. Childress helpfully points out that they've maximized their space potential. It's time for lights out.
Stark and Allison discuss the device while Kevin sleeps. She thinks Stark is too fixated on the artifact. Of course she wants to know what Kevin's dreaming, but not at the expense of the whole town. She thinks they should stop, and tell Carter. Stark refuses to believe it could be causing the town's troubles, and won't turn it off.
Carter dreams that he's trying to kiss Allison, but his efficiency and technique are being criticized by Dr. Childress and Nathan Stark – but then he has a quick flash in his dream about Henry saying, "I'll make it easy for you" and zapping him with a device (which we know from the episode "Phoenix Rising" is a memory-eraser). In another dream, Stark is hitting on Jo (in Mexican clothes and speaking Spanish), when a Zorro-like figure jumps in and rescues her. It's Fargo. Everyone at Café Diem starts awake. This experiment apparently failed. Carter wants to move everyone to Global. Then they notice that several people are unconscious and can't wake up.
At GD, Henry found elevated levels of acetylcholine in Jake's spinal fluid. He explains that acetylcholine controls muscles and is essential for dreaming. The dream didn't kill him, but the acetylcholine led to his diaphragm being paralyzed, and he suffocated in his sleep. He ran some more tests, and found that everyone who's sharing dreams has rising levels of this chemical.
Carter visits Dr. Sueños, who acknowledges he has two prototype devices that affect dreams. He opens the cabinet and finds only one. Carter recognizes it – it looks just like the supposed music therapy device he saw Stark installing in Kevin's room. Carter finds Allison and breaks it to her that Stark's "music therapy" device is causing all the trouble, but to his surprise, she already knows. Carter is hurt that she lied to him. She defends herself, explaining she's terrified for Kevin, and tells Carter he would do the same thing if it was Zoe. Carter starts massaging his forearm, which apparently is going numb from the acetylcholine. He tells her they better get Stark to explain himself – and fast.
Stark calmly explains that the dream device visually interprets the electrical signals generated during REM sleep. He still doesn't believe that this device could be affecting the town. Henry tells them that exactly 50 people have the elevated levels of acetylcholine and Jo reports that there were 50 different dreams reported. Fargo points out that he's not one of the 50, so that Zorro dream wasn't his. Stark chimes in that it sure wasn't his dream. An embarrassed Jo says, "Oh, God." Carter figures out that all the 50 dreamers are all the same pay grade. Allison explains that G3 doesn't really refer to pay grade, but rather to jobs that require set hours so fatigue doesn't compromise safety-truck drivers, reactor techs, network engineers and the like. Carter seizes on that network one – wasn't Childress doing some kind of neural network experiment? Is it possible the neural network somehow amplified Stark's dream device to make them all share dreams? Stark finally acknowledges it's possible, and they should shut down the device. They're off – except Jo, who can no longer move her legs – to visit Dr. Childress, who acknowledges she is doing an experiment on them. She is trying to harness the brain waves that they generate during sleep for problem-solving. Once she understands that her network is working in conjunction with the dream device to cause all these shared dreams and elevated acetylcholine levels, she agrees to shut it down right away. Stark points out that it won't help with the people whose levels are already dangerously elevated. Childress thinks that if they can purge the body of the current acetylcholine, it'll reset its rate of production back to normal levels. Stark devises a method of cleansing but it requires the subject to be in a sealed tank which is then flooded with oxygen-rich plasma fluid. Breathing in the fluid is going to be weird, but it should solve the problem. Or if it doesn't work, the subject will drown. Carter is horrified, but he's exhausted and and losing muscle control, so he doesn't have a choice. In the tank, Carter struggles, and seems like he might drown, but eventually manages to breathe the fluid in, and his acetylcholine levels return to normal. Allison is relieved the dreamers are all going to be okay. Stark is relieved that they can now resume their research.
Carter and Henry are discussing the dreams in Café Diem. Carter mentions he had a dream, which seemed very familiar, of Henry telling him "You're not going to remember anything" and then a flash of light. Henry knows that this is actually a memory, but plays dumb, saying dreams are funny like that.
At the sheriff's office, Jo is opening a gift. The card from Carter says "Glad you're back on your feet," and the package contains a beautiful set of ballet slippers.