Keep the Kleenex nearby, gleeks. Tuesday's new episode of Glee is the start of the long goodbye for McKinley's seniors.

With just weeks until graduation, everyone's got the future on their minds. Rachel (Lea Michele) and Finn (Cory Monteith) may have decided to make New York their next step, but there's a lot more uncertainty for the rest of the gang. Take Kurt (Chris Colfer) and Blaine (Darren Criss), who have yet to discuss the idea of a long-distance relationship, and Quinn (Dianna Agron), whose paralysis may or may not be permanent. Some of the adults aren't exactly prepared to let go either.

Post-graduation plans take shape for three on Glee

TVGuide.com got an early first look at the moving hour — and we're not kidding about the tissue. Here's what you need to brace yourself for (maybe even watch with a good friend):The sweetest throwback to Glee's very first episode.

So as not to completely ruin the surprise, we'll just say this: Remember that warm and fuzzy feeling you felt when you first watched Finn, Rachel, Kurt, Artie and Mercedes sing "Don't Stop Believin'" in the auditorium, and then Mr. Schuester walked in and got all teary-eyed and choked up because he had nearly decided to ditch these kids for a more lucrative career in accounting? (Grrr, Terri!) Yessir, Mr. Schue and New Directions are a tight bunch. Graduation is not gonna be easy for anyone. Unexpected romance for... two pairs! One you might root for, the other... not so much. "It's Not Right, But It's Okay."  Pay special attention to the lyrics. Somebody's angry! Couple's counseling needed?

Darren Criss: Graduation on Glee doesn't necessarily mean goodbye

Boyfriends, girlfriends...um, what about moms and dads? Who will break up? Who will stay together? Can we take a moment from the relationship drama to instead to consider mom and dad? How about a little TLC for the parents of the seniors? Kurt and Blaine haven't discussed the potential heartache of Kurt leaving for New York, and it looks like Kurt and Burt haven't either. Serious tissue alert: Dad's going to to want to open up before it's too late.Brittany and Santana's first duet as a couple. Brittany isn't featured on the cover of Glee's graduation soundtrack, which means she's not a senior or, as the executive producers have previously teased, she's pulling straight Fs. If she and Santana are about to part (is Santana really headed to Kentucky?), no one's blinking just yet — which is great, because instead we get a supremely cool dance from the two Cheerios (backed by the entire squad) to "I Wanna Dance with Somebody." No tears. All awesome. Yay, Brittana!Former enemies bond. If you watched the preview, you can guess who'll wind up in a hug. Also featured: one bromantic toast to the last four years. Check out the seniors singing "How Will I Know" in Tuesday's episode (8/7c on Fox):