Like every episode ever done where a show imagines, "What if black was white and white was black?" the characters all start out as opposites of who they really are but by the end seem on their way to falling into the lives we already know. Meredith shoots tequila. And... scene.
Okay, okay, I'll give you some details. Meredith goes to bed thinking about how people say that life works out the way it is supposed to, and that causes her to have a crazy dream about what her life would be like if her mom was still alive, Chief of Surgery, and married to Richard -- who got together with Ellis so far back in Meredith's life that Mere's last name is Webber and she calls him, "Dad." Mere wears pink and is perky and wants to go into cardio, and seems to have a decent relationship with Ellis. Oh, and she just got engaged to a Buddy-Holly-glasses-wearing version of Alex, who is the peppy Chief Resident. Her Person is April, and everyone is scared of Cristina and they all make a lot of mean cracks about how she somehow managed to drive Burke out of the state when their relationship ended. It sounds like April had a thing for Alex but she assures Mere she's happy for her about the engagement.
As for the rest of the staff: Derek and Addison are still married, and she is about to have a baby. Everyone thinks that they are the picture of a perfect marriage. But Derek hasn't published or run any clinical trials, and his nickname among the residents is, "McDreary." His hair is much more limp than usual, so we know it's fitting. As they day goes on we realize that the two of them are miserable together and that Derek spends all of his nights sleeping alone in his trailer on the land where he wants to build a house one day. Callie is in cardio and is married to none other than Owen, and they have three kids. He is having massive PTSD issues but somehow has managed to convince Callie that he's getting over them. When he flips out and punches his fist into a window, Cristina bandages him up and it turns out she's been doing this for a while, but keeping it secret. He doesn't want Callie to know because she'll leave him and take the kids because she's scared he will hurt them, but Cristina wisely points out that he should probably be nervous about that, too. It's the only real emotion we see from her as otherwise she seems to be an angry, unpleasant loner. Callie winds up on a case with Arizona and they fight about the kid's treatment and seem to hate each other but when everything winds up working out, they seem to have a little spark as they hug and talk about going out for a celebratory drink sometime.
Bailey is nothing like the Bailey we know now but is instead the meek "Mandy" Bailey that we've seen in her first-year flashbacks. She has a surgery that Ellis steals out from under her -- Ellis just won her third Harper Avery and wants to do her fancy award-winning procedure on Bailey's patient. What she doesn't realize is that the guy has complications that mean the procedure isn't ideal, but Bailey is too meek to tell Ellis this herself. She tells Alex instead, but he doesn't pass it along and when Ellis realizes the problem (mid-surgery, with a gallery full of journalists watching), she gets so angry about being made to look dumb in front of the press that she fires Bailey. Or rather, she has Richard fire Bailey.
Oh, and the shooting never happened, so Charles is alive and well and working at the hospital, but instead of pining after Reed, he seems to have the hots for April. (Who is still a virgin in this universe.) (Or so we think.) Jackson is working the ER when a convulsing junkie is brought in mid-overdose, who turns out to be Lexie. Or "Lucy Ball," as she calls herself. Lexie admits to Jackson that she has a half-sister who works there but they have never met and she won't tell Jackson who it is. Instead, she swipes Jackson's security badge and uses it to steal a bunch of drugs before she sneaks out. The problem with doing a bunch more drugs after you've just OD'd is that it's probably going to happen again; it does, and a nice stranger rushes her back to the ER. That good-looking stranger turns out to be Mark.
In an effort to impress her mother after Ellis lays a huge guilt trip on Mere for not focusing enough on surgery, Meredith uses her position as the Chief's daughter to get in on a case with Cristina. Cristina is livid and tries to get her thrown back off, but as she bursts into Alex's office to yell at him about it she finds Alex and April passionately making out and trying to rip off each others' clothes. Cristina winds up doing the procedure with Meredith and the two bicker the entire time; when a complication arises they disagree on what to do and Cristina finally just takes over, sticks her hands in the guy's chest when Mere isn't looking, and fixes the problem. In the locker room afterward, with tensions running high among all of the residents, Mere insults her and makes a comment about Burke, so Cristina shoots back at her the fact that her man and her bestie are hooking up. Alex decides to go cry in the elevator and that's where the freshly-fired Bailey finds him while she's on her way out. The experience seems to have given her a new perspective and she pretty much tells him to suck it up and do what he needs to do to get his life in order. We know that Mandy has just started transforming into Miranda.
Mere goes to Richard, crying and humiliated about the Alex/April thing, and he is trying to comfort her when her mom comes by and tells her that she heard what happened. Mere is shocked until she realizes that Ellis is referring to what happened in the surgery, and after Ellis starts to lecture her Mere finally gets fed up from all of the pressure she's feeling and starts unleashing what is clearly years of pent-up rage towards her mom. Ellis goes crying to Richard later about how she only wants the best for Mere and doesn't know how to talk to her, and he says he'll take care of it. But when he goes to do so, Mere yells at him that she's not letting him make nice on her mom's behalf yet again. She yells that Ellis wants to make everyone around her ordinary, and she has definitely done that to Richard.
Mere is getting ready to leave when she finds Cristina working on "Lucy Ball" in the ER and Mere asserts that they have to crack her chest after her heart stops and all seems lost. After a lot of work the two of them get it beating again, and they seem to have a moment of understanding. They then go to Joe's, where Cristina teaches Mere how to do a tequila shot. After they have a brief bonding moment Cristina heads home, and Mere is left sitting next to Derek, who is dejected after just being informed by Addison that Mark is the father of her baby. The two decide to just be a boy and a girl in a bar doing shots for one evening and the rest, as they say, is history.
Adoption people will tell you that it was meant to be with the baby you adopt, according to Mere's VO. We see her kissing Zola, who is in her PJ's while VO Mere muses that she likes that idea but she thinks everything else in life seems to be the result of just a random series of events. She starts to wonder all of the "What ifs" that start off a show's Weird Parallel Universe Episode that I'm convinced takes place if you leave something on the air long enough. Cristina and Owen both look miserable, both wide awake at night, in bed, as far from each other as they can get without falling off of the edge. The Chief is having an equally tragic evening as he finds a confused Adele in the kitchen and gently leads her back to bed. Callie and Arizona are much happier than that, cuddled up together, sound asleep, while Mere wonders if she'd never have found her true love if she'd chosen a different path for herself. She wonders about her upbringing; about her mom and what might have been if she hadn't gotten sick; about what her life would have been like with a good dad. She puts Zola down to bed, smiles at her sleeping, perfectly-coiffed husband, and falls asleep with all of these questions tumbling around in her head. I don't know about you, but I'm sure that if things had gone differently that would be the end of that and this show would never have reason to exist. That's totally going to be the point of this hour, right?
The next morning, Mere wakes up in the same clothes and with her hair in the same waves as the night before. Once she gets downstairs, however, she's got her hair as straight as a pin and is wearing a bubblegum-pink button-up shirt underneath a cardigan in the same shade. I'm just going to say it: she's a little long in the tooth for this whole look. I think we're supposed to find her bright and cheery and fresh but it's somehow making her skin look a little bit rough. And this is not a knock on Ellen Pompeo, who I think has been looking amazing these past couple of seasons -- better than in the entire series until now, in fact. It's just that this look is that horrible. It's like if I tried to wear something in dusty rose after growing out my bangs. The effect would be that I'd look like I had consumption. Someone had been calling her from downstairs and that someone turns out to be... Ellis. Who is alive and alert and asks Mere if she wants a ride to work or is going with her father. Just then, Richard walks up and gives his "darling" Ellis a kiss good morning, chiming in that he heard his name. So in this strange, pink, backwards Seattle -- Elttaes, if you will -- Richard and Ellis got together early enough that Mere actually calls him "Dad." As Ellis leaves she reminds them to be on time so they don't set a bad example.