We couldn't be more excited to finally get to see the first part of Glee's 100th episode spectacular when it airs tonight! And we're now getting a final sneak peek at what to expect from the episode.

The show has released a new video of scenes from tonight's Season 5, Episode 12: "100," along with the cast discussing what their characters will be up to. Perhaps the most exciting part of the video is getting to see Quinn (Dianna Agron) decked out in her old Cheerios uniform and performing with former partners-in-crime Brittany (Heather Morris) and Santana (Naya Rivera).

"Quinn will be performing with the Unholy Trinity," Dianna Agron tells us. "I did say, 'I'm never going to be a cheerleader again.' Never say never."

We also learn more about the context of the new performance of "Defying Gravity," which the show originally covered back in Season 1. "For this scene, myself, Lea, and Chris — we all are singing 'Defying Gravity' back-to-back-to-back," Amber Riley (Mercedes) explains.

It's official: Tonight's episode is going to totally rock! In fact, if seeing the Unholy Trinity reunited doesn't get you excited, then you should probably check your pulse. 

What are you looking forward to most about tonight's 100th episode? And do you think Santana and Brittany will get back together?

Source: Glee on YouTube