Pakistan, Aug. 1 -- Kaley Cuoco returned to the Big Bang Theory multiverse for the first time in seven years. The actress makes a surprise appearance in the episode 2 of Stuart Fails to Save the Universe - a new TBBT spinoff revolving around comic book store owner Stuart Bloom, who accidentally triggers a multiverse Armageddon.

Episode 2, titled "Spoiler: Zack's in This One," follows Stuart Bloom, Bert and Barry Kripke as they escape the post-apocalyptic Pasadena introduced in the premiere. Their relief is short-lived after they arrive in what appears to be a peaceful reality, only to discover they're wearing devices that shock them whenever they argue or show aggression. After completing a 30-month reeducation programme, they're kidnapp...