Actress Naya Rivera Arrives at the 2014 People's Choice Awards in Los Angeles
Actress Naya Rivera, from the Fox series "Glee," arrives at the 2014 People's Choice Awards in Los Angeles, California January 8, 2014. REUTERS/Kevork Djansezian

"Glee" Season 5 spoilers hint Episode 10 ("Trio") is packed with changes, most of them in threes. Demi Lovato and Adam Lambert suit up in this episode. Chris Colfer joins them as Kurt Hummel, founder of Pamela Lansbury. Songs in this episode include "The Happening" and "Barracuda." Also in this episode, the New Directions psych up a week before the Nationals. And Rachel is still madly upset over Santana's understudy audition.

Spoiler alert: This feature contains spoilers on Glee Season 5, Episode 10, titled "Trio." This new episode airs on FOX on Tuesday, March 4. Read at your own risk. Watch some YouTube clips below and see spoiler photos on IMDB.com.

This could be Demi Lovato's last episode on Glee. The young pop diva is very busy in her music career, so Dantana (Dani and Santana) shippers should take all they can from Glee Season 5, Episode 10. Listen to this YouTube clip of "The Happening" cover (featuring the trio of Lovato, Colfer and Lambert).

In Episode 9 ("Frenemies"), hell broke loose between Santana (Naya Rivera) and Rachel (Lea Michele). As Rachel's understudy in "Funny Girl," Santana should always be where Rachel is. But it seems they cannot be roomies anymore. Watch the Glee 'Trio' promo clip below to see Rachel outside Elliott Starchild's (Adam Lambert) pad. Is she thinking of taking his couch?

"Elliot is stuck in the middle between Rachel and Santana's feud," says the FOX release for Glee 5x10. This is not an ideal trio, but fans would like to see how Elliott deals with this diva fight. In addition, Elliott may have to explain to Blaine (Darren Criss) what his "kiss selfie" with Kurt (Glee 5x9) was all about.

As for the adults in the show, it looks like Mr Schue (Matthew Morrison) and Ms Emma Pillsbury (Jayma Mays) are pregnant. They are probably the central trio in this episode. However, earlier spoilers revealed this will be Emma's last episode on Glee. Mays said, "We knew it was coming last year."

"One week 'til Nationals," Mr Schue says in the FOX promo video. How will McKinley High's New Directions fare before the big competition in Los Angeles? Fans should not miss the next new episode: Glee Season 5, Episode 11, aka "City of Angels."

Watch: Glee Season 5, Episode 10 ('Trio') FOX Promo Clip on YouTube

See Demi, Adam and Chris all suited up in the promo video below.

Here are the songs in Glee Season 5, Episode 10: "The Happening" by The Supremes, "Danny's Song" by Loggins and Messina, "Jumpin' Jumpin'" by Destiny's Child, "Barracuda" by Heart, and "Gloria" by Laura Branigan. This new episode airs March 4 on FOX.

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