The bulk of the episode dealt with Leonard (Johnny Galecki) and Penny (Kaley Cuoco-Sweeting) who are inadvertently forced to examine their relationship when Sheldon points out that they've been engaged for a year, and haven't even set a wedding date.
At first the couple get defensive of their choice, saying they've just both been really busy. Leonard points out that, since they love each other, "It doesn't matter if we get married tomorrow or a year from now or 50 years from now."
But that's when things get serious. With a devilish smile Penny tells Leonard that she doesn't have any plans for the evening, and without hesitation Penny and Leonard decide to hop in their car and elope in Vegas.
However their trip quickly gets awkward when Leonard, who is clearly having second thoughts, confesses to Penny that, years ago, he got drunk and kissed another woman. It was before they were engaged but while they were still dating.
Penny grills him on why he chose this moment to tell her, and assumes it's because he wants to sabotage their Vegas wedding, but Leonard assures her that he's totally committed to the idea, and they agree to go through with it. They drive on, looking really unsure of their plans and their future together.
And if that was the cliffhanger, it would have been a good one. But nothing could prepare us for the devastation we were about to endure.
Sheldon's (Jim Parsons) relationship with Amy (Mayim Bialick) has been a challenging one. Sheldon doesn't understand important things (like basic human emotions) and Amy does her best to deal with his weirdness. They both love each other, but it's clear to everyone except Sheldon that Amy is unhappy with how slowly their relationship has been moving along (they've been dating for two years and haven't even had sex).
So when Sheldon and Amy are kissing, and Sheldon interrupts to ask whether or not he should start watching The Flash, she gets understandably angry, but Sheldon cannot work out why she's so mad.
Amy then disappears for the bulk of the episode only to return for a video chat with Sheldon in the closing minutes of the show. A distraught Amy manages to tell Sheldon that she needs time to "step back and re-evaluate our situation."
It's a punch in the gut to Sheldon and everyone watching. After Amy terminates the call, Sheldon turns with an unusual sadness and looks at a statue of Gollum sitting on his desk.
"Well Gollum, you're an expert on rings," Sheldon says to the little figurine, before reaching into his desk. "What do I do with this one?"
And that's when he pulls out a beautiful engagement ring in a black box. It's also when everyone at home began sobbing uncontrollably.
The rest of the episode dealt with the show's other various relationships, which are at totally different stages. Raj (Kunal Nayyar) and Emily (Laura Spencer) -- who are still dating and getting to know each other -- and on the other end of the spectrum there's Howard (Simon Helberg) and Bernadette (Melissa Rauch) who are happily married, but are still sharing a home with Stuart (Kevin Sussman), who isn't the ideal housemate.
Raj has decided to break up with Emily because she's simply too weird for him. So when she takes him to make out in a graveyard (like a weirdo) Raj tries to pull the trigger and break things off. However, he ends up chickening out and telling her that he loves her instead.
Meanwhile, Bernadette and Howard sit Stuart down to talk with him about moving out. However, things start off on difficult footing when Stuart reveals it's his birthday. Instead of kicking him out, they present him with a birthday cupcake.
So by the end of the episode, everything is up in the air. Penny and Leonard are driving to Vegas to get married, despite the fact they know they aren't ready, Raj wants to break up with Emily, but is now deeper into the relationship, and the only happy couple are stuck being miserable because they're too nice for their own good.
And let's not reiterate what happened with Sheldon. It's just too sad…