The new spin-off series of The Big Bang Theory, Stuart Fails to Save the Universe, was introduced to the audience with its first visuals at the CCXP Mexico City event. Starring Kevin Sussman, Lauren Lapkus, Brian Posehn, and John Ross Bowie, the series combines elements of comedy and science fiction and will premiere on HBO Max in July. It was also announced during the panel that musician Danny Elfman will create an original theme song for the series.

Stuart Fails to Save the Universe revolves around Stuart Bloom, played by Kevin Sussman, the owner of a comic book store, and will tell the character's story after the conclusion of The Big Bang Theory. In the original series, Leonard (Johnny Galecki) and Sheldon (Jim Parsons) would frequently visit the store. In the new series, Stuart accidentally triggers a multiverse Armageddon by breaking a device created by Sheldon and Leonard, and he tries to restore reality.

Brian Posehn told the audience on stage about the title character: "The fun part is watching him fail every week." Kevin Sussman emphasized the development of Stuart's romantic relationship with Denise, played by Lauren Lapkus, saying, "When The Big Bang Theory ended, our relationship was just beginning; now you’ll see where it goes."

Stuart's group of friends joining him on this adventure includes his girlfriend Denise (Lapkus), geologist friend Bert (Posehn), and persistent quantum physicist Barry Kripke (John Ross Bowie). During their journey, they will encounter alternate universe versions of characters from The Big Bang Theory. The original series aired for 12 seasons and concluded in 2019.

Sussman notes that Stuart "takes on a leadership role in this process" but adds that he is "not very successful at it." The actor added about the character: "I’m doing my best, but I’m far from my comfort zone." Under the visuals shared on HBO Max's Instagram account, it read, "If you fail the first time, try again in another universe."

The creators, writers, and executive producers of Stuart Fails to Save the Universe are Chuck Lorre, Zak Penn, and Bill Prady. The series is co-produced by Chuck Lorre Productions and Warner Bros. Television. The Big Bang Theory previously spawned the Young Sheldon spin-off, which ended in 2024 after seven seasons. Georgie & Mandy's First Marriage, derived from Young Sheldon, is currently airing its second season on CBS.