UPDATE (12/4/2013): Good news, folks! Harry Shum Jr. and new mom Heather Morris have both filled up their dance cards for the milestone episode! Murphy tweeted that "Harry is IN!" on December 4, and later that day wrote, "Heather is IN for Glee 100th!"

Original story: Fantastic news from the land of Glee! Creator Ryan Murphy is currently planning the show’s landmark 100th episode, and he’s invited back all of the original cast members to participate. The show-stopping ep will be  Season 5, Episode 12, and it’s likely air on Tuesday, March 18, 2014. A number of them have said yes already, and Ryan’s quickly taking to Twitter to announce which ones.

On November 3, the Glee boss tweeted, “ALL The Glee Originals received invites today to be in our 100th episode! More to follow.

Barely a couple hours later, he gave the first update. “Amber is IN for episode 100! More to follow...” Of course, we really didn’t have any doubt that Amber Riley (Mercedes) would want to participate. Therecently-crowned Dancing With the Stars winner has returned to the show many times in the past.

A few hours after that, Ryan wrote, “Mark is IN for the 100th! More great news coming...” Mark Salling’s (Puck) return also doesn’t surprise us one bit, and we’re pretty sure that Harry Shum Jr. (Mike) will be back, too.

However, we can’t say the same about Heather Morris (Brittany). After giving birth to her son, Elijah, in late September, Heather seems to be leaving acting behind. But surely she could make it back for just one more episode?

Also up in the air is Dianna Agron (Quinn), who made headlines earlier this year for saying she wasn’t asked to be a part of Glee’s Season 5, Episode 3 tribute to the late Cory Monteith (Finn). Well, Di, it appears you’ve been asked this time. Ryan still hasn’t commented on Dianna’s status, but sources tell TVLine that the actress very much wants to be a part of the show. She just has to make sure that she’s available on the dates they need.

Who’s In:

Amber Riley (Mercedes)

Mark Salling (Puck)

Harry Shum Jr. (Mike)

Heather Morris (Brittany)

Who’s Not:

No one so far.

Unknown:

Dianna Agron (Quinn)

Sources: Ryan Murphy on Twitter, TVLine


Beth Douglass is an Associate Editor at Wetpaint Entertainment. She's our resident Glee expert and loves celebrity kids. Follow her on Twitter and Google+!