Credit: Adam Rose/FOX ©2010 Fox Broadcasting Co. Photo: New Directions in Season 2, Episode 7: "The Substitute"

It’s Tuesday, and that means it’s time for a little Glee Tease-O-Rama!

Tonight’s episode — “Original Song” — is a BIG one: Several plotlines that have been slowly simmering finally come to a simultaneous boil. Regionals is upon us, delivering a major showdown between McKinley High’s New Directions, the Dalton Academy Warblers, and the Sue Sylvester (Jane Lynch)-headed Oral Intensity; the glee club’s efforts to craft an original grow increasingly urgent; and in classic Glee style, there’s a KISS THAT CHANGES EVERYTHING!

Let’s just get this out there: We love this one. “Original Song” packs the kind of wow factor we’d expect from a season-ender — and there are still more episodes to come!

Here’s what you can look forward to:

Rachel (Lea Michele), who has already been pushing New Directions to tackle an original composition (“My Headband,” anyone?), succeeds in getting other glee clubbers to follow her lead — thanks to a certain someone’s scheming that puts the glee club’s back against the wall when it comes to their Regionals performance playlist. Brace yourself for ditties from the musical minds of Santana (Naya Rivera), Puck (Mark Salling), and Mercedes (Amber Riley). (The latter’s effort, “Hell to the No,” is so freakin’ iPod-ready we can’t even begin!) Rachel also digs deep down to express herself in song — you’ve sampled the online versions of “Get It Right” and “Loser Like Me,” right?

Glee creator Ryan Murphy teased us way back in summer 2010 about what he had in mind for the original music. “I think it has to be organic,” Murphy told us. “I don't think you could do it beyond the episode. I think that it would have to be an assignment, as opposed to suddenly they just break out their own songs. I don't think you would understand it. I think it would have to have an architecture behind it.”

There are some familiar tunes in the episode as well: Get ready to add songs from Maroon 5, Hey Monday, P!nk, Songseed (Google ‘em), and The Beatles to your favorite playlist.

What else can we tell you?

— There’s a nearly brand-new judging panel at Regionals to be reckoned with. Anchorman Rod Remington is back in all his camera-perfect glory, joined by “recent Tea Party candidate, Twitterer, and homeschooler” Tammy Jean Albertson (played in a patriotic red business suit and stylish specs by comedienne extraordinaire Kathy Griffin, who channels a familiar former vice presidential contender). Also at the table? Sister Mary Constance (played by Broadway icon Loretta Devine), a nun/writer who came to her calling after an unexpected former career in adult entertainment.

Quinn’s (Dianna Agron) campaign to become the prom queen — with Finn (Cory Monteith) as her king — heats up, and our favorite former knocked-up Cheerio seeks out an unlikely alliance to further her newly relentless agenda.

— My Chemical Romance is revealed to be quite socially conscious.

— Someone gets punched! And before you ask, Dave Karofsky (Max Adler) is not in this one.

— And finally, you’ve probably heard about an unexpected death rocking the Glee’s world. Yes, a certain singing voice is silenced forever. Is it shocking? Yes, you probably didn’t see it coming. And the repercussions are so mondo-uber-mega-huge that we’re putting duct tape over our mouths right this second.