Jenna Fischer has explained that certain members of The Office worked overtime to make sure Steve Carell‘s appearance on the final episode was a secret.

“They had a scene at our table read … but it was a placeholder,” Fischer said on Wednesday’s episode of the Office Ladies podcast, which she hosts with Angela Kinsey, the actress who played Angela.

Carell portrayed office manager Michael Scott for the show’s first seven seasons, but he had left for the final two. He turned up again at the wedding of two of his former employees, Angela and Dwight (Rainn Wilson) in the May 2013 finale.

Fischer, who played the paper company’s receptionist Pam (until she was promoted), explained that creator Greg Daniels even filmed a fake version of the episode to fool them.

“He was afraid that if he turned in any footage of Steve Carell on the show before it aired that NBC would make promos out of it and ruin the surprise,” she said.

They ended up seeing it the day before it aired.

Early on, she said, there had been another obstacle: Carell wasn’t into reprising his role, although Daniels had asked him early in that final season.

“But Steve was reluctant,” Fischer said. “He felt like Michael’s story had really ended. He didn’t want to open it back up again, and he especially did not wanna come back after two years and have this finale episode be about him.”

Carell eventually agreed because of the storyline he was pitched. It made sense Michael would be at the wedding, because of the relationship between the characters. Scott had been uncomfortably close to his employees.

“It was a creative reason that was supported by history, you know,” Fischer said.

The Hall Pass actress had not even told Kinsey, her real-life coworker and best friend, or others in the cast.

“It was really hard not to tell you … and you did not find out until he showed up on set that day,” Fischer said.

Kinsey said she found out as it happened.

“The set PA turned to me and said, ‘Steve is here.’ … I said, ‘What?’ Kinsey said. “And I opened the door, and there he was — he was sitting in hair and makeup.”

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At least one of Fischer’s costars was in on the surprise, though.

John Krasinski, who played Dwight’s office rival and Pam’s husband, Jim, told PEOPLE in June 2013 that he had “flat-out lied” about Carell’s return, too.

“I lied to [David] Letterman!” he said. “I have to apologize to him for that at some point. It was just one of those things that we all vowed and had to protect. Look what happened – it was the best.”