Spoilers:
Update. Here is the recap of the episode.
Source
In a deceitful bid to secure a Regionals’ victory for his Dalton Academy Warblers, New Directions’ arch rival Sebastian tries to blackmail Rachel to pull out of the singing competition. When a devastating event shocks the McKinley community, it causes the students to reevaluate their priorities, and inspires Mr. Schuester to reveal an uncharacteristic moment from his past. Meanwhile, a reinvigorated Quinn tries to regain her position on the Cheerios, Finn and Rachel make a sudden decision about their future together, Kurt helps a troubled friend through a difficult situation, and Will gets a surprising new ally.
Hmm. Last time, the devastating event was when Sue's sister died. Many fans are speculating that when Dave Karofsky returns, he will attempt suicide or come out and get beat or gay bashed. While it would make for a powerful storyline, I can't see them going there. Didn't Ryan Murphy say they would never go down the suicide route? Then again, he also said we wouldn't have any guest stars this season.
Kurt helping a troubled friend definitely sounds like Dave. Is the devastating event something different entirely?
Post your theories below!