Recap
At the comic book store, after realizing that they are in a telepathic universe, Stuart warns the others that they need to control their thoughts because everyone can hear them. Bert immediately derails the conversation by trying to remember a film and its actress, leading Denise to admit that she found Phoebe Cates' pool scene in Fast Times at Ridgemont High attractive. She says sexuality exists on a continuum, prompting Kripke to inadvertently place Rob Lowe on his own.
Returning to the more pressing matter, Stuart explains that he has been reading the instruction manual that came with the replacement vari-state quantum entanglement device. He believes the manual is another message from whoever has been guiding him. He explains that the group has failed to find its way home because the device only moves laterally between realities, whereas they need to travel along the fourth-dimensional axis: time. The machine Sheldon and Leonard designed was never completed, and Stuart theorizes it requires a "steering wheel" capable of directing them to a time before everything went wrong. Kripke suggests cobbling one together from a satellite controller using parts from Caltech's engineering department.
At Caltech, they once again encounter Ramona Nowitzki at reception. When Stuart asks for Howard Wolowitz, she finds no record of him. She agrees to check again, although her audible thoughts reveal that she is only pretending in order to be polite. When Stuart asks for a moment to confer, Ramona says, “I’ll be here,” while privately lamenting that her marriage to a drummer has left her trapped in this job for its health insurance. Denise suggests that Howard may not exist in this universe, while an online search by Bert turns up no trace of him. Bert does, however, find Bernadette Rostenkowski, who may be able to help them.
They find Bernadette at a strip-mall dance studio, where she openly insults the children in her class for dancing like baby hippos. After one girl silently wishes her dead, Bernadette asks whether she thinks about her mother with that mind. Stuart observes that Bernadette is probably not a microbiologist in this reality, prompting Kripke to privately mock Stuart’s powers of deduction. Denise chides Kripke for the thought, but he replies, “I think ’em wike I see ’em.”
Bernadette does not recognize the group or the name Howard Wolowitz. When Bert privately wonders what has happened to her, she bitterly explains that her alcoholic mother pushed her into beauty pageants and fed her diet pills, all so she could become Miss California Quiznos 1999. While Stuart and Denise’s thoughts express sympathy, Bert is fixated on Quiznos. Bernadette complains that she is now teaching “pampered little maggots” to tap-dance when the only dancing they will ever do is on a pole, then orders the distressed children to shut their “brain holes.” Stuart apologizes for wasting her time. Bernadette cheerfully wishes them a good day while thinking that it would not have been a waste had they killed her, then returns to teaching the “future eating disorders.”
Back at the comic book store, Bert and Kripke eat Quiznos. Bert demonstrates one advantage of telepathy by speaking through his thoughts while his mouth is full. When Stuart and Denise join them, Stuart blurts out that they were having sex, reasoning that everyone would hear him think it anyway. The couple enthusiastically recall that telepathy allowed them to know exactly what the other wanted. After Bert asks how they plan to obtain the necessary components, Stuart confidently proposes breaking into the engineering department, but his thoughts betray mounting panic: they cannot get inside, do not know what they need or how to assemble and operate it, and would not know where to go even if they succeeded. Stuart asks if they have any questions, but after hearing their “captain” unravel, Kripke replies, “No, I think we’re good.”
Later, Kripke is tired of trying to figure out a way to deceive people, declaring that there is no trickery in a world with telepathy. He demonstrates by asking Bert to think of a card and correctly identifying it after hearing Bert think of the Three of Clubs. Stuart suggests blocking their thoughts with something like Magneto's helmet. After Kripke silently disparages the idea as more comic-book nonsense and wishes someone would kill him, the other three think that they would be happy to oblige. Denise leads the group in meditation, hoping that they can clear their minds. Her own thoughts immediately reveal that she considers the idea hopeless. A jumble of thoughts about food, digestion, clothing, Macbeth, cars and dry cleaning confirms that none of them can quiet their minds, so Stuart abandons the exercise.
The four enter Caltech carrying the device and telepathically singing “Come On Eileen” to hide their true objective. At reception, Stuart tells Ramona that the song was playing in their car and has become an earworm. She understands and grows tearful as she begins singing “Dust in the Wind” in her mind. Stuart claims that David Saltzberg at UCLA asked them to deliver the device to the engineering lab. Ramona directs them upstairs, and the group resumes its mental singing. In the corridor, Kripke claims they need a variable-impedance controller circuit, while inwardly admitting that he has no idea what he is talking about. When some scientists pass them, the group covers its thoughts with “The Girl from Ipanema.”
Inside the engineering lab, they discover lab-coat-wearing versions of themselves gathered around another vari-state quantum entanglement device. All eight exclaim, “What the fuck?” Lab Coat Stuart says they have to go, and Lab Coat Kripke activates his group's machine, causing a bubble to envelop the four lab-coat doubles. The original Kripke grabs his group's device from Stuart and follows in their slipstream, drawing his companions into the same wormhole.
The two groups race through realities the original travelers have previously visited. They first run through the market in post-apocalyptic Pasadena beneath the giant moths. The lab-coat group jumps to the AI-controlled universe, where their Kripke pushes an elderly woman aside and is punished by his AI shock collar. The original four arrive moments later. Still writhing from the shock, Lab Coat Kripke again activates his device.
Both groups pass through the magical universe, where villagers are preparing to burn Neil deGrasse Tyson at the stake, and then the tropical paradise, whose formerly peaceful inhabitants are still brawling. The lab-coat group then reaches the pastoral universe where humans evolved from cattle. Delighted by the grass, the four doubles abandon the chase and begin eating, causing the arriving original group to trip over them. All eight fall into a tangled heap alongside the two devices.
When everyone gets up, the two Denises initially find themselves beside the wrong groups. Stuart retrieves his device, while Lab Coat Kripke recovers the other. The two Stuarts simultaneously demand to know who the other group is. Each wonders whether the other is the mysterious Stuart who visited his comic book store, but both say that another version of Stuart recruited them as the only person capable of saving the universe. With both groups possessing a quantum device, Stuart concludes that their guide lied to them.
Bert's counterpart suggests that their unseen guide may have distrusted the first Stuart and recruited another as a failsafe. Before he can offer a second possible explanation, Lab Coat Stuart stops him and insists that every moment they spend arguing places reality at greater risk.
A third bubble arrives carrying military versions of Stuart, Denise, Bert and Kripke. On Army Stuart's orders, Army Kripke intimidates his lab-coated counterpart into surrendering his device. As the soldiers activate one of the devices and flee, Army Stuart glances back at Stuart before disappearing. The original group follows them into the bubble, leaving the lab-coat group stranded. With no machine, the four doubles kneel down and begin eating grass.
Stuart’s group emerges in a war zone amid ruined buildings, armed soldiers, gunfire and explosions. Bert immediately says, “No, thank you,” and Denise urges Stuart to hit the switch. He activates the device, and they escape.
They arrive in what initially appears to be a normal comic book store, only to discover that they have the lower bodies of horses. Even the life-size NASA astronaut figure by the door is half man, half horse. When Denise says, “Oh, no,” Bert corrects her: “I think you mean, ‘oh, neigh.’”
