‘Stuart Fails To Save the Universe’ Just Gave Fans Their First Live-Action Flash, and Sheldon Isn’t Who You’d Expect
Superhero references have always been baked into the DNA of “The Big Bang Theory,” with Sheldon Cooper’s obsession with the Flash serving as one of the show’s most consistent running jokes across twelve seasons. From wearing Flash T-shirts to literally dressing as the character to power through exhaustion, Sheldon’s connection to the Scarlet Speedster was never subtle.
That connection has now paid off in a way longtime fans probably never expected. HBO Max’s multiverse-hopping spinoff “Stuart Fails to Save the Universe” has spent its first season sending former comic shop owner Stuart Bloom and his friends careening through wildly different alternate realities, and this week’s episode leaned directly into one of the original show’s most beloved running bits.
Episode 9 of “Stuart Fails to Save the Universe,” titled “Spoiler: We Couldn’t Get Green Lantern,” premiered September 17 and features Sheldon Cooper replaced in one alternate universe by his own superhero icon, the Flash, brought to life in full live-action costume. Given how heavily Sheldon leaned on the character throughout “The Big Bang Theory’s” original run, from hallucinating the Flash for motivation to dressing up as him for a Justice League costume contest, the swap plays as a clever payoff for longtime viewers rather than a random gag.
The episode also brings back Mayim Bialik as an alternate-universe version of Amy, once again married in this particular reality, adding another familiar face to the ever-expanding roster of “The Big Bang Theory” veterans making appearances across the series. That mix of legacy cameos and DC-flavored world-building has become something of a signature for the show as it moves through its ten-episode debut season.
The Flash has officially appeared in live action in ‘The Big Bang Theory’ Stuart spinoff show. https://t.co/UnfelkJErE
— DCU Brief (@DCUBrief) September 18, 2026
“Stuart Fails to Save the Universe” follows comic book store owner Stuart Bloom, once again played by Kevin Sussman, after he accidentally breaks a device built by Sheldon and Leonard and unleashes a reality-shattering catastrophe. Alongside girlfriend Denise (Lauren Lapkus), geologist friend Bert (Brian Posehn), and physicist Barry Kripke (John Ross Bowie), Stuart has spent the season bouncing between increasingly bizarre alternate realities in an attempt to fix the damage.
Surprise! Episode 9 of ‘Stuart Fails To Save The Universe’ takes palce entirely in the DC universe! Multiple DC characters appear for cameos. https://t.co/twlF2dSiRl
— DCU Brief (@DCUBrief) September 18, 2026
That premise has already delivered plenty of unexpected DC-adjacent detours throughout the season, including a previous episode that introduced a live-action Batman villain widely believed by fans to be Mr. Freeze, based on the character’s icy goggles and armored design, though HBO Max has not officially confirmed the character’s identity. Combined with this week’s Flash reveal, the series appears increasingly comfortable using its multiverse premise as an excuse to dip into recognizable DC iconography.
First trailer for the ‘Big Bang Theory’ spin-off series ‘STUART FAILS TO SAVE THE UNIVERSE’.
— DiscussingFilm (@DiscussingFilm) May 13, 2026
The series follows Stuart who must restore reality after he breaks Sheldon & Leonard’s new device and causes a Multiversal Armageddon.
Releasing July 23 on HBO Max. pic.twitter.com/x6rPJA2gFT
Created by Chuck Lorre, Zak Penn, and Bill Prady, “Stuart Fails to Save the Universe” marks a significant tonal departure from previous “Big Bang Theory” spinoffs like “Young Sheldon” and “Georgie & Mandy’s First Marriage,” trading nostalgic sitcom storytelling for genre-bending sci-fi comedy. Reviews have generally praised the show’s willingness to take creative risks with beloved characters, with critics noting that giving side players like Stuart, Denise, Bert, and Kripke the spotlight has produced some of the franchise’s most surprising material yet.
With the season set to wrap on September 24 after its ten-episode run, fans still have one more week to see how Stuart’s multiverse-spanning journey resolves. Between legacy cameos, a live-action Flash, and a mysterious DC villain still awaiting confirmation, the show has clearly leaned into fan service in ways the original series never could.
What do you think of Stuart Fails to Save the Universe introducing a live-action Flash?
Have something to add? Let us know in the comments!
