Who doesn’t remember the greatness of The Big Bang Theory?

It was the type of sitcom I would impatiently anticipate every week, waiting for those glorious 30 minutes where I would sing along to the incredibly catchy theme song and feel as if I was actually spending time with Sheldon (Jim Parsons), Leonard (Johnny Galecki), Penny (Kaley Cuoco), and the rest of the group.

It’s been a awhile since the 12-season show ended, leaving many fans, including myself, to believe that was the end of the story for these characters.

Besides the fan-favorite prequel, Young Sheldon, and the currently-running Georgie & Mandy’s First Marriage, fans were originally left in the dark as to whether there could be any potential spinoffs featuring the characters we know and love… until now!

Although you shouldn’t expect Parsons to return as Sheldon Cooper, there is finally a new show centering around a beloved cast member of the original series. Stuart Fails to Save the Universe is HBO Max’s newest comedy about Stuart Bloom (Kevin Sussman), the comic book owner. Remember him? Here he will be joined by three other familiar faces from The Big Bang Theory as they go on a mind-bending journey after Stuart accidentally creates a multiverse from using a device built by Sheldon and Leonard. What a mess!

With the first episode premiering tonight at 9 p.m. ET on HBO Max, here’s DECIDER’S guide to every actor from The Big Bang Theory that you can expect to show up in this outrageous comedy!

1. In The Big Bang Theory, Sussman played the comic book store owner Stuart. In that series, Stuart was a side character who would share moments with the main cast every now and then, but here he takes the lead. In the comedy, Stuart must lead Denise, Barry, and Bert on a trip through the multiverse in order to reset the universe.

   Aside from his role as Stuart, Sussman has had prominent roles on other television shows like Lessons in Chemistry and Better Call Saul.

   Want to learn more? Follow Kevin Sussman’s instagram at @kevsussman.

2. Lauren Lapkus joined The Big Bang Theory towards the end of its run, but didn’t fail in making an impression. Lapkus played Denise, who worked at Stuart’s comic book store, where they eventually entered a relationship. In the new series, Denise will join Stuart on his journey, despite starting the season as a separated couple. Let’s see if a trip through the multiverse can save their relationship.

   Lapkus is known for her roles in Orange is the New Black and Good Girls.

   Want to learn more? Follow Lauren Lapkus’s instagram at @laurenlapkus.

3. Brain Posehn is back as Bert Kibbler, the Caltech geologist. The socially awkward professor will return in Stuart Fails to Save the Universe in a pivotal role. Here, he will join Stuart on his journey through the multiverse. Knowing his character, we can’t wait to see what shenanigans Bert will get up to away from reality.

   Posehn has over 100 acting credits to his name, including his many seasons on The Sarah Silverman Program.

   Want to learn more? Follow Brian Posehn’s instagram at @brianposehn.

4. John Ross Bowie’s Barry Kripke had an interesting relationship with Sheldon on The Big Bang Theory. Barry and Sheldon were often competitive at Caltech, with the two frequently going back and forth between friends and enemies. In the spinoff, Barry jumps at the chance to further his career by being able to discover all the multiverse has to offer.

   Bowie has many other television credits, including a lead role on the sitcom Speechless.

   Want to learn more? Follow John Ross Bowie’s instagram at @johnrossbowie.

5. Arguably the most iconic guest star on The Big Bang Theory, Christine Baranski has returned. In the original sitcom, the Emmy winner famously played Sheldon’s mother. Baranski can be seen briefly in the trailer, but her role in Stuart Fails to Save the Universe is currently unknown. Anyone should consider themselves blessed to see Baranski in any reality or multiverse!

   Baranski is a Hollywood legend, starring in films like Mamma Mia! and having an iconic role on CBS’s The Good Wife.

6. Fans of The Big Bang Theory will be happy to know Wil Wheaton will be making an appearance in the show. Wil Wheaton played an exaggerated version of himself in the original sitcom, and was a long-running villain in the earlier seasons, before making peace with Sheldon. Although his exact role hasn’t been revealed, he was seen in the trailer.

   Wheaton has starred in classics like Stand by Me and Star Trek: The Next Generation.

   Want to learn more? Follow Wil Wheaton’s instagram at @itswilwheaton.

7. Fans might not remember Josh Brener’s role, but he appeared in two episodes of The Big Bang Theory. He played an employee of Stuart’s comic book store. However, Deadline confirmed Brener will not reprise his role of Dale. Instead, he will be playing a character named Trevor.

   You might recognize Brener for his roles on Silicon Valley and The Last of Us.

8. Joshua Malina played Dr. Siebert, the president of Caltech. Dr. Siebert would often get frustrated with Sheldon’s behavior. In the multiverse, it might be reasonable to expect Malina might be playing a different role, or perhaps a different version of his character.

   Malina is best known for his role in The West Wing.

   Want to learn more? Follow Joshua Malina’s instagram at @joshmalinasjoshmalina.