Brace yourselves, Gleeks. Heartbreak is on the way.

Following last night's mediocre episode of this Fox hit, the series is making it as clear as possible that one long-time couple will not survive the October 4 installment. How do we know? It's titled "The Break Up."

Will a new job offer split Will and Emma apart? What about the long distance getting in the way for Blaine and Kurt or Rachel and Finn? All three relationships appear to be on the line in this episode teaser.

Which will come to an end? Which do you want to come to an end? Watch now:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.