“I was there the moment when Leonard and Penny met. He said to me that their babies would be smart and beautiful. And now that they’re expecting, I have no doubt that that will be the case,” Sheldon says, accidentally revealing the baby news even before Penny’s parents know. “I apologize if I haven’t been the friend that you deserve. But I want you to know, in my way, I love you all.”
While Johnny Galecki is putting down the comic books for good as he says goodbye to experimental physicist Leonard Hofstadter, he's poised to return to another iconic role one more with the expanded season two order of Roseanne spinoff The Conners coming to ABC this fall. Galecki reprised the role of David Healy, ex-husband to Sara Gilbert's Darlene, for a handful of episodes in the show's first season and the door was definitely left open for more. Despite Galecki telling TV Line in February that he wouldn't consider jumping in full-time—"I think I need a little bit of space from being a series regular again," he said—he's hoping to "visit as much as possible." And Gilbert, who serves as EP on the series, remains hopeful as well. "I know he loves doing the show. I love having him. We have a magical time together," she told the outlet in January. "I would anticipate that he would do some [episodes] but I don't want to speak for him."
Regina King reprised her role as Janine Davis in “The Retraction Reaction”. Bob Newhart returned as Arthur Jeffries in “The Proton Regeneration”. Dean Norris reprised his role as Colonel Williams in “The Tesla Recoil”. Brian Thomas Smith returned as Zack in “The Bitcoin Entanglement”. Brian George guest starred as Raj’s father, Dr. Koothrappali, in “The Confidence Erosion”. Joshua Malina reprised his role as President Siebert in “The Monetary Insufficiency”.
After Sheldon reminds the guys about the time they mined Bitcoin without him, the guys go on a quest to find their suddenly valuable missing cryptocurrency. They realize the currency is on a laptop which Leonard gave to Penny when they dating, which she then gave to her ex-boyfriend Zack. After Leonard and Penny go to Zack's apartment, he shows them a seven-year-old video that Penny recorded on the laptop soon after she broke up with Leonard. Leonard is touched by the video which shows a drunk Penny lamenting the break-up of her relationship with him.
When Raj misses out on a job at the planetarium, his father says he has no confidence because Howard always makes fun of him. Raj distances himself from Howard and later gets the job. Howard is hurt by this (even after apologizing to him) and tries to make amends with Raj after his first performance at the planetarium but, when he sees him get a date, he leaves without speaking to him, thinking that the latter's life is better without him. Meanwhile, Sheldon and Amy try randomly dividing up wedding tasks, but they keep arguing. The only thing they can agree on is to get married, so they decide to just get married at City Hall. However, Sheldon decides that he wants a first dance with his new wife and they go home to plan their wedding.