"New Normal" alum Andrew Rannells will stir up lots of drama during his guest appearance on an all-new upcoming episode of "How I Met Your Mother."

According to an official episode synopsis, Rannells will play Darren, a guy at Barney and Robin's wedding who intentionally stirs up trouble among the gang. It is also worth noting that Marshall will finally arrive at the Farhampton Inn in the same episode.

After HIMYM fans more than likely complained about being disappointed during last week's episode, executive producer Craig Thomas dropped a new spoiler hint for the season 9, episode 13 of the CBS comedy, entitled "Bass Player Wanted."

He tweeted, "Folks are asking if The Mother is in the next new #HIMYM. I could say 'No spoilers.' Or I could just say, 'Yes. A LOT.'"

Nonetheless, fans should not take that as proof that she will be in every episode moving forward, although Thomas promises that viewers will get to see a lot of the mother during episode No. 200, which airs in late January.

"You're going to be so sick of her by the end [of the series]," said the executive producer to TV Line, adding that new series regular Cristin Milioti is "the star" of "How Your Mother Met Me," which is told from her character's perspective.

CarterMatt.com notes that "Bass Player Wanted" did not have an air date or a position in the lineup of episodes for a long time. However, after being swapped around a few times, producers decided to schedule its premiere as the fall finale airing on Dec. 16.

"How I Met Your Mother" S9E13 is set to air on Monday, Dec. 16 at 8 p.m. EST on CBS.