Many of us who are superfans of The Officehave often wondered why Dunder Mifflin needed to bring in a replacement for Pam's second maternity leave.

In the Office Ladiespodcast with Jenna Fischer and Angela Kinsey, the best friends and co-stars broke down "Pam's Replacement,"episode 7 from Season 8. (Fischer had been on a brief podcast hiatus after breaking her shoulder.)

Fischer pointed out that during Pam's first maternity leave, she was just doing the receptionist job. But by the eighth season, she's the office administrator and still covers some receptionist duties; in essence, Pam is now doing all of the behind-the-scenes jobs that keep the office running smoothly.

To recap, Pam is getting ready to go on maternity leave, but she's feeling insecure about being replaced. Plus, Pam worries that Cathy, played by Lindsey Broad, is younger and more attractive that she is, and that Jim will be attracted to her. Cathy will even be sitting at Pam's desk, right next to Jim.

Meanwhile, in the warehouse, Andy, Darryl, and Kevin — or Kevin and the Zitsas they're affectionately known — are having a jam session. Robert California asks to join them before kicking them all out once his old bandmates show up. 

Pam's pregnancy fears land on Jim and Cathy.

Fischer said even though she was actually pregnant while filming the episode, she wasn't upset by any of the jokes about pregnancy. In fact, she appreciated that the dialogue deals with some of the insecurities pregnant people may have around their attractiveness at the time. (The episode was written by Allison Silverman Jones, who was pregnant at the time.)

"I thought this episode was so well written and so beautifully highlights some of those insecurities," Fischer recalled.

Pam enlists the help of Dwight to determine if Jim finds Cathy attractive, but asking Jim outright — not to mention Dwight’s rude crotch-grab— just does not seem to work. 

Who is Mike Tibbets?

One of the ways Pam, Dwight, and Kelly try to find out how Jim really feels about Cathy is the set-up test. Pam asks Jim which one of his friends he would set Cathy up with. Right away, Jim says Mike Tibbets, aka "the most boring-looking guy I know." Of course, Jim is already onto Pam's plan and picks Mike on purpose.

"That is a trigger for me," Fischer recalled. "So, filming the scene at Kelly's desk where she pulls up the photo of Mike Tibbetts — I don't know if you watched the bloopersof it, [but] we couldn't get through it."

Fischer said that she and Mindy Kaling did not get to see the prop photo of Mikebefore they recorded the scene. When they pulled up the photo, it was of a regular-looking guy with a receding hairline, black-framed glasses, and a wide smile. Overall, he's not terrible — "I don't see what's so ugly about him; he's got the broad face of a brewer," Dwight comments — but probably not a love match for Cathy.

"The scripted line that Mindy is supposed to say is, 'Maybe he would be better if he changed his hair.' But the person they picked had no hair," Fischer said. "We never came back from it. I don't know if I've ever laughed so hard, like my stomach hurt. My giant pregnant stomach."

Kaling even sent in a voice recording to the podcast recalling her difficulty with the scene and its absurdity — specifically, the ridiculousness of Kelly's comments. In the episode, the line that made it to airing was, "I mean, I guess he'd be okay with hair. OK, you should see if he'll get hair plugs."

Eventually Pam, Jim, and Dwight head to a local pharmacy for a lie-detector test. Jim’s blood pressure is elevated, so  the couple decides to leave and call his doctor after grabbing Cece a toothbrush.

The warehouse band gets a new member — and then a new band.

Also in this episode, Andy, Darryl, and Kevin are joined — finally! — by their too-cool-for-school boss Robert California, played to icy perfection by James Spader. They're thrilled and convinced they'll now be BFFs for life. But not so fast! 

Robert California's real friends show up, and they're real musicians — on the show and IRL. The on-screen crew includes Robin Swenson, Linda Taylor, and Steve Moore. Moore's backstory is what will win you trivia night.

Moore, also known as the Mad Drummer, was cast by NBC for a part in Robert California's band after Moore's video, "This Drummer Is at the Wrong Gig,"went viral. (He replaces Kevin on drums in this episode.) Kinsey said she read interviews with Moore after his appearance in which he noted how nice and down-to-earth everyone was at the filming. 

• 50 revelations about 'The Office' from the 'Office Ladies' podcast
• Jenna Fischer shares the 2 times she laughed the hardest while filming 'The Office'
• Jenna Fischer and her husband chat about his cameo on 'The Office'
• Jenna Fischer fought hard to cut this storyline from 'The Office' (and won)
• Here's what Jenna Fischer and Angela Kinsey call the 'sweetest of sweet moments' from 'The Office'

"He said this: 'Every person I encountered seemed to be in a great mood and happy to see me,'" she said. 'And this made all the difference, as I was obviously out of my element and a nervous wreck.'"

Kinsey points out that this isn’t the first time Kevin was replaced in his band — remember Scrantonicity vs. Scrantonicity 2? 

"I saw a few other people talk about this online, and I had been thinking the same thing," Kinsey said. "This is the second time Kevin has been pushed out of his own band. He was in Scrantonicity! They kicked him out. He had to form Scrantonicity 2. Kevin and the Zits, he just got kicked out of."

Eventually, Darryl, Andy, and Kevin are seen outside the warehouse playing music together and embracing "The Zits" name.

Scranton's hometown style is strong in the episode.

Kinsey pointed out that it appeared the prop crew had made a trip to Scranton before the episode. She said she saw items from Gerrity’s Supermarkets and Wegmans, both of which have their headquarters in Scranton. But the prop that she found the most curious was a blank book being read by Dwight. Kinsey, who had many scenes with Rainn Wilson, said she believed that the book was a last-minute addition. She said Wilson loved props; she surmised that he'd told the crew he needed a prop for the scene and was handed the blank book. 

"So it might have been a last-minute idea," Kinsey said. "And to avoid any problems with clearance, [prop master] Phil Shea probably gave him a book with no cover or title."

While Fischer and Kinsey are in the final stretches of The Officeepisodes, the best friends promised that the Office Ladies would continue. They are planning some unique content, and even considering a "Dear Office Ladies" advice spin-off podcast. Would you want advice on your own office life? Let them know! 

You can stream episodes of The Officeon Peacockand follow along with the podcast every week on Earwolf, Apple Podcasts, or Stitcher.