Vari-State Quantum Interference Device

The Vari-state Quantum Interference Device is the machine at the center of the multiverse catastrophe. Built at Caltech by Leonard Hofstadter, Sheldon Cooper and Howard Wolowitz, the device was damaged when Stuart Bloom accidentally knocked it off a table, triggering the collapse of his original reality into a post-apocalyptic nightmare.

When an alternate Stuart appears from another reality (Stuart Prime), he first refers to it as “some kind of quantum entanglement thing”, while Raj later identifies it as a Vari-state Quantum Interference device. In a comic book written by Stuart Prime, it is referred to as a Vari-state Quantum Entanglement Device, while an advertisement for the device in that same comic refers to it as a Vari-State Quantum Device.

The device appears capable of opening passages between different realities and transporting people caught within its interdimensional bubbles. Stuart and his companions do not fully understand how it works, and its operation can be affected by the rules of the reality they have landed in, such as requiring magic to function in the magic world. The machine usually travels with the group, though who is carried along depends on who is close enough when the bubble forms.

101 “Spoiler: Gary Dies”

In the post-apocalyptic reality of 101 “Spoiler: Gary Dies”, an alternate version of Stuart appears at the Comic Center of Pasadena and tells Stuart that the catastrophe can be undone if he reaches the machine at Caltech. Before he can explain fully, Stuart Prime is pulled back through a wormhole.

At Caltech, Stuart, Bert and Denise encounter Raj, who has spent years imprisoned, studying what went wrong. Raj confirms that Leonard, Sheldon and Howard built the device and believes he can use it to restore reality. After the group reaches the guarded machine, Raj is shot by Kripke before he can use it. Stuart and Denise try to follow Raj’s notes, but the device activates before they can read the final instruction. The machine creates an interdimensional bubble that pulls Stuart, Bert and Kripke into another reality, leaving Denise behind in the post-apocalyptic world.

102 “Spoiler: Zack’s in This One”

In 102 “Spoiler: Zack’s in This One”, Stuart, Bert and Kripke arrive with the device in an apparently peaceful Pasadena that is actually controlled by an AI overlord. Kripke concludes that Denise must have been too far from the interdimensional bubble to travel with them.

Because none of them truly understands the machine, Bert and Kripke try to find Sheldon and Leonard at Caltech, hoping they can explain how to use it. Meanwhile, Denise later finds the device at the comic book store and contacts the Resistance, believing it may help defeat the AI overlord.

When Stuart admits the device cannot save this reality and can only help them escape to another one, the Resistance turns on the group. During the chaos of a drone attack on the Resistance headquarters, Kripke tries to flee with the machine, but Stuart, Denise and Bert catch up just as it activates. This time, the bubble separates them into two pairs: Stuart and Denise, and Bert and Kripke.

103 “Spoiler: Bert is Magic”

Stuart and Denise arrive with the device in a reality where magic is real in 103 “Spoiler: Bert is Magic”. When Kripke later tries to activate the machine, it doesn’t work, leading him to conclude that a universe unconstrained by the laws of physics may require magic to make the device work.

Stuart and Kripke seek help from Bernadette Rostenkowski, a master sorceress who has been stripped of her powers. After tricking Stuart into helping restore her magic, Bernadette transforms into a five-story-high demon and tries to capture the device so she can rule every world.

As Bernadette attacks the comic book store, Stuart urges Bert, who is a powerful wizard in this reality, to get the machine working. Bert does not know the correct spell, but his simple commands are enough to activate it. The device transports Stuart, Denise, Bert and Kripke to another reality, with Kripke still in penguin form until they leave the magic universe.

104 “Spoiler: Stuart Makes a Wallet”

In 104 “Spoiler: Stuart Makes a Wallet”, Stuart appears to have been separated from the device and institutionalized in a reality where he is made to see the other universes he experienced as delusions. After he is released into a seemingly perfect suburban life with Denise and their children, Stuart finds a Stuart Fails to Save the Universe comic book planted by Stuart Prime at the Comic Center of Pasadena.

The comic retells the device’s origin, showing Leonard, Sheldon and Howard building a vari-state quantum entanglement device before Stuart accidentally damages it. It also warns Stuart that he must escape the “prison” he is trapped in. An advertisement in the comic leads him to order a “Vari-State Quantum Device” from the Inter-Dimensional Novelty Company of Southfield, Michigan.

Tired of your current universe? Travel between realities. Impress your friends. Scare the girls. With the Vari-State Quantum Device, you can now take the trip of a lifetime to a nearby alternate reality. Explore your existence in another universe. Will you be a titan of industry? A jet-setting playboy? An elite athlete? There’s only one way to find out.

When Stuart activates the new device at home, he and Denise are pulled into another layer of the same constructed reality, where they awaken in pods alongside Bert and Kripke. After realizing they are literally trapped in a scene from The Matrix, Stuart tears through the illusion and finds the real device waiting in a vast white space. With no way to know where it will take them next, Stuart activates the machine and the group escapes together.

This page has been updated up to episode 104 Spoiler: Stuart Makes a Wallet