Inside Jim Parsons and Mayim Bialik’s ‘Effortless’ Young Sheldon Return (Exclusive)

Warning: This post contains spoilers from the two-part series finale of Young Sheldon.

While young sheldon’s two-part series finale on May 16 was the perfect send-off for the Cooper family, it will also be remembered for perfectly merging Sheldon Cooper’s past and present.

During the second half of the finale…reprised their roles fromthe big bang theory as adult Sheldon and his wife Amy, respectively. The bickering couple now have kids whose pursuits aren’t as intellectual as their parents’: Leonard loves hockey, and their daughter, who is never named, wants to take acting classes.

Getting Parsons, 51, and Bialik, 48, to revisit their characters was a relatively simple proposition, Young Sheldon executive producer and co-showrunner Steve Holland recently told PEOPLE.

“I think they were both excited. Jim’s obviously been a part of the show. He’s an executive producer. He’s been the narrator,” Holland says, adding that “I think Mayim literally said, ‘Anything you want me to do, I’ll come there and do.’”

Working around Parsons’ schedule proved a bit tricky, particularly given his and Bialik’s appearances in the finale were much more than just 30-second cameos. The actor is currently starring in the Broadway production of…and Celia Keenan-Bolger.

In the end, Parsons flew to Los Angeles during a day off from rehearsals, shot his scenes with Bialik, then flew back to make rehearsals the next day. Their scenes were also shot earlier than the rest of the finale scenes to accommodate the two actors’ schedules.

But the result was worth it. While all their lines were scripted — nothing was left to chance — Parsons and Bialik deliver the sharpest, wittiest dialogue in the finale.

After Amy ribbed Sheldon in a scene about whether the book he’s writing is a “memoir” or a “fantasy novel,” the two exchanged some memorable zingers. Yes, Sheldon may have been technically present when Amy gave birth to one of their children, but during labor, the Nobel Prize winner Zoomed into a seminar.

“You were taking forever to dilate,” he said in the scene, adding, “I’d already made my contribution, and need I remind you, it was on your birthday.”

This irritated Amy, who was still miffed her husband won’t come with her to catch their son Leonard’s hockey game. “I would love to dissect your brain to see which part of your brain is missing,” she exclaimed.

“Or you’ll find an all-new structure that no one’s ever seen before — an evolutionary leap forward,” he shot back, adding as she leaves the room in a huff, “All these years, and the passion is still there.”

Sheldon and Amy first met in the season 3 finale of The Big Bang Theory. While Sheldon only agreed to meet Amy then because his friends essentially blackmailed him, the two would fall in love and eventually get married in the season 11 finale.

Stepping back into their roles after after almost five years was pretty seamless, with Holland marveling at their performances.

“They’re both so talented,” he says, adding, “I think they would say that there was some nerves about stepping back into these characters and that they weren’t quite sure they would find their rhythm. From watching them do it, it felt so effortless.”

“Just watching them work, sitting, editing and watching the takes, they make so many smart and interesting choices on each line. It was just really a joy to watch,” he adds.

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