HBO Max will launch Stuart Fails To Save The Universe on Thursday, July 23 at 9 pm ET, and the spinoff will roll out over ten episodes. The teaser for the series was unveiled Wednesday during the Warner Bros. Discovery Upfront presentation in New York, giving fans their first look at comic book store owner Stuart Bloom’s latest problem.

That problem is not small. Stuart breaks a device built by Sheldon and Leonard, and the accident triggers a multiverse Armageddon that leaves him trying to restore reality. The series follows him as he is helped by his girlfriend Denise, geologist friend Bert and quantum physicist Barry Kripke, with alternate-universe versions of The Big Bang Theory characters also folding into the story.

The opening clip starts at The Comic Center of Pasadena storefront, where Brian Posehn’s Bert asks Stuart, “How is it out there?” and later says, “I think there’s room for improvement.” Another Stuart then appears with a warning that he has “only got a few minutes to explain this…. so you gotta focus,” before adding, “I’m you from another stream of reality.” The teaser also includes a cameo of Johnny Galecki in a comic book drawing, a quick signal that the new series is leaning hard into the same universe that made the original show such a durable hit.

The spinoff is written and executive produced by Chuck Lorre, Zak Penn and Bill Prady, and it is produced by Chuck Lorre Productions in association with Warner Bros. Television. Lauren Lapkus plays Denise, Posehn plays Bert and John Ross Bowie plays Barry, putting familiar names into a setup that mixes comedy with a very large crisis.

For now, the headline is simple: Stuart is the one who has to fix it. He is not just dealing with a broken machine, but with a cascade that has pulled in other versions of his world, and the teaser makes clear the story will turn on whether he can put reality back together before it keeps splitting apart. Every Thursday after July 23, viewers will get another episode to see whether he manages it.