Jack was just getting used to the idea of being a daddy and now he's about to learn he's a grandaddy.

Next week's episode of Will & Grace is titled "Grandpa Jack" and features the return of Jack's son, Elliott (Michael Angarano) who reveals he has a son of his own, Skip (Jet Jurgensmeyer).

We can only imagine how big Jack's gasp will be when he learns that he has a grandchild.

No only does "Grandpa Jack" have family drama, it's also the episode where Jane Lynch and Andrew Rannells guest star. The two play counselors at a conversion therapy camp called Camp Straighten Arrow. The episode description says that "Skip needs the kind of help only Will (Eric McCormack) and Jack can provide," but whether Skip is actually a camper at Straighten Arrow is unclear.

Lynch and Rannells are just the latest celebrity guest stars to swing by the new season of Will & Grace. Dear Evan Hansen's Ben Platt played a millennial crushing on Will in the second episode and this week's installment saw the return of Harry Connick Jr. as Grace's ex-husband, Leo.

In a bonus digital after-show, Lynch spoke about her time on the show and how she has been friends with Megan Mullally since the '90s and that she originally auditioned for a small role on the series back in the day.

"I didn't get it [the role]. It was kind of a cattle call experience, and it was for a lesbian. I was shuffled through, shuffled out and never heard from them again. It's really nice to be a part of the show now."

Will & Grace airs Thursdays at 9/8c on NBC.