How Jim Parsons 'blindsided' the cast of 'The Big Bang Theory' when he decided to leave the hit sitcom

This is how The Big Bang Theory ended... not with a whimper, but a bang. Jessica Radloff's oral history, The Big Bang Theory: The Definitive, Inside Story of the Epic Hit, reveals the chain reaction of events that happened after the show's star, Jim Parsons, decided that Season 12 would be his final year as Sheldon Cooper. That choice apparently "blindsided" his co-stars and resulted in hurt feelings that took some time to heal.

Naturally, Parsons didn't set out to rock the boat. As he told Radloff, he desperately needed a change of scenery. "I don't think there was a part of me that actually thought I would do more seasons [of Big Bang] after the twelfth," Parsons said in the book. "I was ready to… get out of the security of the show to fully find out what was next for me."

Parsons found a kindred spirit with ready-to-move-on co-star Simon Helberg, who stresses that neither of them thought that their departures would preclude the blockbuster sitcom from continuing. "That didn't mean that we, in any way, expected that the show would certainly end or that there wouldn't be any kind of attempt from the producers or the studio or the network to keep the show running, whether or not we were involved," Helberg said in the oral history.

Apparently, the producers felt differently. When Parsons informed series creator Chuck Lorre and executive producer Steve Molaro of his decision after the table read for the Season 12 premiere, they immediately decided the show would end with his exit. "There was never a question about continuing on without him," Molaro told Radloff. "The show was this ensemble, and the thought of doing some strange version without him didn't seem right."

But Radloff reported that the producers waited nearly a week before telling the rest of the cast, who only found out at a meeting where Parsons himself had to tell everyone that he was leaving. Immediately afterwards, Kaley Cuoco visited Lorre in tears. "We cried for hours," she said in the book. "We thought we were going to do another year, so all of a sudden your life kind of flashes before your eyes. I looked at Chuck and said, 'What are we going to do?' I couldn't breathe. It just felt like a death."

In fact, Cuoco and Jonathan Galecki — who formed the show's core trio alongside Parsons — were so upset with their co-star that the first run-through of the season became an awkward affair. "None of them were talking between scenes," Molaro said. "Kaley could barely make eye contact with Jim during the runthrough, but they got through it."

Reflecting on the situation years later, Galecki says that the cast didn't object to Parsons's decision to leave, but they were bothered that he didn't approach them before telling the producers directly. "I just disagreed with how it was handled," the actor said now about the fateful meeting where they learned the show was ending. "We thought we were going into Chuck's office to talk about renegotiating, and then Chuck tossed the baton to Jim. And Jim was shocked and obviously caught off guard."

As they put the uncomfortable start to the show's final season in the rearview, the Big Bang cast eventually rallied to send the show out on a high note. "They loved the show so much and it was such a special place… that they didn't want it to end ugly," showrunner Steve Holland said in the oral history. "If this was going to be the last season, they were going to put aside their anger and frustration and differences and enjoy every minute of it."

The cast was certainly on better terms by May 1, 2019, when they taped the series finale ahead of its May 16 premiere. Cuoco and her co-stars shared numerous photos and emotional messages on social media.

"Thank you, Apartment 4A, for being a home to so many dreams come true, to so many friendships made," Parsons wrote on his own Instagram post, proving that fences can be mended even after dropping a bombshell personal announcement.

The Big Bang Theory is currently streaming on HBO Max