In the season eight finale, Sheldon and Amy get into a fight about commitment on their fifth anniversary. Amy tells Sheldon that she needs to think about the future of their relationship, unaware that Sheldon was about to propose to her. Season nine sees Sheldon harassing Amy about making up her mind until she breaks up with him. Both struggle with singlehood and trying to be friends for the next few weeks until they reunite in episode ten and have sex for the first time on Amy's birthday.
'The Big Bang Theory' executive producers Chuck Lorre, left, and Steve Hollland and stars Kevin Sussman, Mayim Bialik, Jim Parsons, Kaley Cuoco and Kunal Nayyar stand to the left of 'The Big Bang Theory' stage plaque, with executive producer Bill Prady, star Melissa Rauch, executive producer Steven Molaro and star Johnny Galecki, director Mark Cendrowski and star Simon Helberg on the right. (Photo: Warner Bros.)
According to Steve Holland who is the show-runner starting with this season, Wil Wheaton will return in this season since his absence from Season 10. And this has confirmed to be true since it has been stated that he reappeared in "The Proton Regeneration" (S11E6), along with Professor Proton, their first appearances since "The Opening Night Excitation" (S9E11) and "The Celebration Experimentation", respectively and a span of 43 episodes and a span of 37 episodes, respectively. Wil also returned in the 15th episode. Wil will also return for Sheldon and Amy's Wedding.
"The Skank Reflex Analysis" "The Infestation Hypothesis" "The Wiggly Finger Catalyst" "The Russian Rocket Reaction" "The Rhinitis Revelation" "The Good Guy Fluctuation" "The Isolation Permutation" "The Flaming Spittoon Acquisition" "The Shiny Trinket Maneuver" "The Recombination Hypothesis" "The Beta Test Initiation" "The Werewolf Transformation" "The Hawking Excitation" "The Stag Convergence" "The Countdown Reflection"
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.