A very special guest star made an appearance on The Big Bang Theory Season 8 Episode 15.
The latest installment of television's top-rated sitcom (titled "The Comic Book Store Regeneration") centered on Wolowitz receiving some stunning news as him and everyone around him got ready for the reopening of Stuart's comic book store.
Penny (Kaley Cuoco-Sweeting), meanwhile, sought to teach Sheldon (Jim Parsons) how to "let it go," yet she could not follow her own advice after she learned something infuriating about Amy.
What could it have been?!?
Follow the prompts of the video here to watch The Big Bang Theory online and find out now!