‘Big Bang Theory’ Spinoff Adds 3 to Cast — Including 2 ‘Big Bang’ Alums

HBO Max’s Big Bang Theory spinoff, Stuart Fails to Save the Universe, is adding three new recurring guest stars — two of whom will look very familiar to fans of the original CBS sitcom.

Ryan Cartwright (Kevin Can Wait), Josh Brener (Silicon Valley) and Tommy Walker (Danger Force have joined the cast of Stuart Fails to Save the Universe, Deadline reported Wednesday.

Cartwright will play Kyle, a comic book nerd and daily patron of Stuart’s comic book store, while Walker has been cast as Gary, Denise’s new boyfriend. Meanwhile, Brener will take on the role of Trevor, which has not been as clearly defined to the public.

The Big Bang Theory fans will recognize Cartwright and Brener from previous guest-starring roles on the original sitcom — Cartwright played Penny’s community college classmate Cole in an episode of Season 6, while Brener appeared in two episodes during Seasons 5 and 6 as comic book store employee Dale.

Previously announced series regulars for Stuart Fails to Save the Universe include Kevin Sussman as Stuart Bloom, Lauren Lapkus as Denise, Brian Posehn as Bert Kibbler, and John Ross Bowie as Barry Kripke.

Stuart Fails to Save the Universe picks up after the events of The Big Bang Theory, following the titular comic book store owner as he’s “tasked with restoring reality after he breaks a device built by Sheldon and Leonard, accidentally bringing about a multiverse Armageddon,” according to the official logline. “Stuart is aided in this quest by his girlfriend Denise, geologist friend Bert, and quantum physicist/all-around pain in the ass Barry Kripke.”

“Along the way, they meet alternate-universe versions of characters we’ve come to know and love from The Big Bang Theory,” the logline continues, and “as the title implies, things don’t go well.”

Stuart Fails to Save the Universe was created by The Big Bang Theory‘s Chuck Lorre and Bill Prady in partnership with writer Zak Penn (The Avengers).

“I wanted to do something radical that would take me out of my comfort zone,” Lorre said in a statement last month of the new spinoff. “Something the characters on The Big Bang Theory would have loved, hated and argued about.”

Prady added in another statement, “The process of writing this show with Chuck and Zak has been damn fun, and I’m certain that joy will come through the screen. Putting characters we loved from The Big Bang Theory into a complex science-fiction story with the kind of mythology that those characters love while maintaining the comedic elements is incredibly satisfying.”

This will be the third Big Bang Theory spinoff. Young Sheldon ran from 2017 to 2024, while Georgie & Mandy’s First Marriage kicks off Season 2 on Oct. 16 on CBS.