At a dinner with Arizona and Callie's parents, Arizona's dad is annoyed by Mark's presence, calling him "the sperm donor." Callie wants to say grace. Callie's mom also doesn't really want to hold her granddaughter.
Alex is doing a presentation on the African children he's treating. One is Zola, a baby girl born with spina bifida. The other residents are annoyed that Alex is getting so much attention. He gets a slow clap.
Derek takes a look at Zola. She's been in an orphanage. Teddy talks to the older brother of a young boy who appears to have a hole in chest. You can see his heart beating through his chest. Cristina is in awe.
She runs to Hunt and says she needs to get herself back in the race for chief resident. He tells her she needs to apologize to Teddy. Cristina doesn't understand what she needs to apologize for.
Hunt and Stark are about to treat a little girl and Stark notes that April is trying to explain to the girl in Swahili that they're trying to help. Stark mocks her for trying to learn a new language.
Cristina apologizes to Teddy for going over her head on Callie's surgery. Teddy asks if she means it or if she's saying it to get back on her service. When Cristina asks if it really matters, Teddy says it does.
Arizona's dad has put together a schedule for the wedding weekend, down to the minute. Arizona asks where the moment of silence is, and her dad says there was no time. Arizona wanted to observe the moment for her brother, Timothy. Mark shows up late and annoys Arizona's dad. Callie's dad welcomes him more, but says he'll knock him out if Sloan refers to him as his "father-in-law" again.
Callie's mom again avoids holding the baby. Her dad steps in and takes Sofia.
Avery is complaining to Lexie about "cleaning up mouse poop" in the chief's testing. Lexie assures him they'll get FDA approval soon and he'll soon be working on real patients. She, meanwhile, is practicing to remove sutures on Teddy's patient without puncturing his heart.
Teddy goes to Hunt and asks for 20 good reasons why she shouldn't let Cristina back on her service because she's nearly ready to cave and needs Cristina's skills. Hunt can't think of one and says she should put Cristina back on her service. She says Cristina got lucky with Callie's surgery, but that she's dangerous and it could have been disastrous.
Alex gives Derek and update on Zola. Meredith gives Derek notes on the second wave of Alzheimer's trial patients. When Derek leaves, Alex warns Meredith that whatever she did with the trial could be really bad, no matter how minor. She says she didn't doing anything and tells him to "shut up about it."
April tries to tells Stark about the African girl not eating and he doesn't want to hear about it. She tells him he promised that they could work together and it "wouldn't be weird." He assures her he's treating her exactly like other residents. They both get an emergency page about the girl and go check on her. She's vomiting blood and April jumps into action.
Callie and Arizona are trying to focus on the big picture and not having to deal with their parents after two more days.
Stark and April are operating on the girl, who has internal TB (in addition to AIDS). April has the right suggestion for treatment.
Derek is operating on Zola with Alex, and mentions to Alex that Meredith was the right choice for the Alzheimer's trial all along. Alex looks upset but says nothing.
Teddy, meanwhile, is talking about her boyfriend who's in town and how she's just "enjoying what he's offering while he's offering," because he'll soon be off to some other part of the world.
Avery is checking on his mice and talking to them. He sees one is unconscious.
Callie shows her mom a veil she made to look like the one she wore at her wedding, but her mom doesn't have a favorable reaction. She tries to muster enough joy to say, "It's lovely." She finally says that there's nothing "about a wedding to a woman or a baby out of wedlock" that is for her. Callie cries and tells her, "I'm your daughter." Her mom says it's devastating to raise and love a child "and know you won't see that child in heaven." She tells Callie, "This isn't a wedding. It isn't right." She leaves, saying, "I can't be here. I just can't."
Arizona sees Teddy's patient's older brother sitting in the hallway. He's devastated, saying this is his only brother and he doesn't want to lose him. She says she understands.
Stark finds April in the cafeteria making a "sticky yellow mess." She's trying to make a porridge made in Africa. Stark mocks her at first for that, too, but when she passionately explains why she's doing what she can for her patient, he's speechless.
Callie's dad says he's tried to reason with her mom, but Callie tells him he has to go. He doesn't want to, but she gives him a hug and send him on his way.
At their house the next day, Alex isn't speaking to Meredith. He says he's practicing keeping his mouth such. She says she didn't tamper with any data. But he realizes she switched the syringe so some sweet old lady would get the drug. He tells her she's jeopardizing the hospital's reputation and that of every doctor there. He leaves when Derek shows up.
Sloan comes and tells Callie the minister was in an accident and won't be able to make it. Callie is upset and says the whole thing is off. It was too hard to find a minister willing to marry them in the first place.
Avery shows the chief an X-ray and a CT he did on the mouse. They couldn't see anything in it, so he did an MRI, too. That's $8,000 worth of scans. They realize they're putting the device in the wrong place, based on the scans.
Derek is holding Zola when Meredith comes into the room and he asks her to hold the baby. Her neuro exam is good after he put in her shunt. He asks Meredith if they can adopt Zola. He says he was holding her and she stopped crying. He said he couldn't imagine her being with any other parent or family. She's stunned.
Bailey shows up at Callie's place to find Callie distraught. She says the wedding is off and it's a joke. She can't have a priest, doesn't have a minister. She says it's "a couple of girls playing dress-up."
Bailey tells her she doesn't need all those specific things to make a wedding. She says God is everywhere, so she doesn't need to be in a church. She says her mother hasn't caught up to God yet. She goes on to tell Callie more about what really makes a marriage. Bailey says she got legally to a man in a church and, "look how well that turned out."
Lexie assists Teddy on the boy's heart surgery. Cristina is amazed at Teddy's work, but they say nothing to each other.
Stark pulls Hunt aside and puts in a good word for April, saying that she has the "kind of caring that can't be taught." He says the hospital would be lucky to have her as the next chief resident.
The chief thanks Avery for his work on the mouse and they celebrate as the mouse twitches and comes back to life. He tells Avery he might get his own slow clap one day.
Sloan goes to pick Arizona up and she's upset that her brother is missing her wedding. She tells him all her time is accounted for and she needs a minute to miss her brother.
Derek and Meredith are going through a ton of adoption paperwork. There is a big list of things they need to do to prove they're suitable to adopt. He says there's something they can cross off the list right now. Meredith says she didn't want to do that, but Derek says, "It's for the baby." We next see them walking into a courthouse and Derek says, "Let's get married."
Bailey is nervous as the wedding is about to begin. She's going to officiate. Arizona's dad walks her down the aisle and Sloan follows by walking Callie down. Bailey asks who gives "this bride to this bride" (Callie to Arizona), and Sloan says, "That'd be me."
Meanwhile, Derek and Meredith are in front of a judge who's working through a marriage like it's a bit of a chore. They don't have rings. He stamps a couple of pieces of paper and says that "by the laws of the state of Washington..." they're now husband and wife. The judge shakes Derek's hand and says, "Congratulations."
At their wedding, Callie and Arizona exchange rings and the whole bit, and walk back down the aisle together. At the wedding reception, Hunt mentions that April is in the running for chief resident. The rest of the doctors laugh a bit. The chief, meanwhile, talks to Cristina about how surprised he is that she's not the front runner for chief resident. Cristina then tells Teddy she's sorry for being such a brilliant surgeon and sitting by while ruining her chances at chief resident. Teddy says Cristina still doesn't get it.
Teddy's boyfriend tells her he's got a job offer at a prestigious hospital in Germany. He says he accepted on one condition: That they have a spot for his incredibly talented cardiothoracic surgeon.
Derek and Meredith are visiting the baby they're going to adopt. Derek doesn't want to leave, even though they're going to miss the wedding reception. He's too busy holding and kissing the baby.
Callie's dad, meanwhile, shows up to the reception, saying that he's been dreaming of dancing with her on her wedding day since she was little, so he turned the car around and came back to have his dance. Callie smiles and dances with her dad.