Guess Who's Coming to Dinner

 is the fifth episode of the twelfth season and the 250th overall episode of Grey's Anatomy.

Short Summary
In the midst of the sisters' dinner party, Maggie ditches her cooking duties to rush to the hospital. Meanwhile, April steps in to help cook as an attempt to avoid Jackson and Arizona nervously waits to find out more about Callie's new girlfriend.

Full Summary
Arizona and April notice that Callie and Penny have arrived. Arizona says she needs more liquor.

Meredith opens the door and is shocked to see who Penny is. Despite this, she greets Penny politely and invites them in. She offers them drinks. Callie's on call, so she gets club soda with lime. Penny tries to decline as well, but Callie says she's driving, so she encourages Penny to have white wine. Meredith goes to get it. As Meredith walks away, she hears Penny say she wants to leave. Callie responds that everyone will love her.

Amelia wonders where Maggie is just as she comes in. Maggie says she has to pee just as Amelia says the food still looks like ingredients. She wonders when dinner will be. Maggie says that Amelia can start chopping something, but Amelia says she's better off managing the guests. Alex says it'll be a disaster. Maggie tells Meredith to take over while she goes to pee. Stephanie points out the wine glasses in Meredith's hands and asks if she was going to do something with them. She tells Amelia Callie and Penny's drink orders and hands the glasses off to her. Amelia's curious about Penny, though, and asks Meredith if she's nice.

Arizona empties the rest of the wine bottle into her glass and asks if there are more bottles. Alex says the place looks nice with the re-model. Meredith offers him and Jo drinks. Jo asks for a margarita, so Meredith gets out the blender to make one. Alex says she's being weird and asks what's wrong. She denies that anything's wrong. Jo says she's not being weird, she's being nice ... to her ... which is weird.

While Meredith watches from the kitchen while blending the margarita, Callie introduces Penny to April and tells her about Jackson and their rocky relationship. Amelia comes up and gives them their drinks. She hugs Penny and tells her it's great to meet her. Amelia tells them to stand by for food. After she walks away, Callie says Amelia can be volatile, but she's great.

Alex asks Meredith again if she's okay. She says she's fine, but he says she's acting like she's in a hostage video. Meredith says she needs to make drinks and she's possibly having a dinner party with no dinner. Maggie dismisses herself again to pee.

Seeing Maggie headed to the bathroom, Callie tries to stop her to introduce her to Penny, but Maggie quickly dismisses herself. Once she's gone, Callie tells Penny about how Maggie accomplished a lot when she was young. Callie sees Meredith with snacks and says she wants one. She also offers one to Penny. Penny tells Meredith she has a great house. She asks if she's lived there long. Meredith explains that she grew up in the house and she's been in and out since then. Penny puts together that she moved back there after Derek died.

After Meredith has left, Callie starts to tell Penny about Derek. Penny pulls her aside and asks her again if they can leave. Callie thinks Penny's nervous about meeting Arizona. She says she'll introduce them, which she does.

Meredith grabs a picture of herself and Zola with Derek and runs up the stairs. She goes into her bedroom, looking at their marriage post-it and then goes to the toilet, where she remembers the day Derek died. She then splashes water on her face and looks at herself in the mirror.

Maggie knocks on the bathroom door and says there are people in the other bathrooms, so she needs to come in. She comes in and starts peeing with Meredith still in there. She thinks she's being punished for having sex with an intern. Amelia then comes in and asks why Maggie's not cooking. She says she has a UTI, but Amelia just tells her to get some Pyridium and woman up. Maggie wants to go to the hospital because she's not sure what else Andrew might have given her. Statistically, there's probably a skank or two among the women he's slept with. Maggie says no one wants her cooking their food and they walk out, still arguing.

Arizona tells Penny about her childhood moving around and Penny says she also moved often for her mother's job while Callie answers her phone and steps away. Arizona says imagine telling classes her name was Arizona. "No, honey. Not where you're from. What's your name?" Penny concedes that Arizona had it worse.

The bell rings and Meredith lets in Jackson. She offers him a drink and he asks for whisky. When he sees that she's distracted, he offers to get it himself. On his way, he runs into April. She didn't know if he was going to be there. Jackson doesn't want to talk about it right now, but tells her he's staying at Ben and Bailey's, but he'll probably be getting a hotel room. Arizona then comes up and asks to steal April away.

Arizona tells April that she met Penny and likes her. While she says that, April tells her about Jackson staying with Ben and Bailey. Arizona says Penny's great and Callie's happy and she's drinking. She asks if April's with her. April takes Arizona's glass and says she's way ahead of her.

Jo sees Stephanie sitting and says she hopes she ate before she came. Jo says she has every right to be pissed. Stephanie walks past her and starts talking to Jackson. Jackson asks Stephanie how long he has to stay before he can sneak out. She says it would be 20 minutes, but as it's a dinner party, his empty seat will give him away.

Amelia looks at the food and says she doesn't know what to do with it. She suggests they just order pizza. Alex asks Meredith again if something happened with Maggie or the kids. Meredith tells Amelia they're not ordering pizza because there's plenty of food there. Amelia says everyone loves pizza. Arizona asks who she's trying to impress. She says Penny will roll with it, because she's a delight. She then suggests that she should date Penny. Amelia says it's ill-advised. Arizona says Callie picked a pretty Penny and Alex asks her how much she had to drink. Amelia then asks if she should order ten pizzas. April then offers to cook because she needs something to do. She recruits Jo to assist. She tosses carrots to Jo and tells her to cut them. Amelia says she could kiss April and April says someone should. Meredith offers to help and April tells her to wash and slice apples. April says once Jo's done chopping, she should go to the store for cheese. Jo instead calls Isaac because running errands is scut and interns to scut.

Alex says Meredith doesn't know how to cook. She says she's a surgeon and knows how to use a knife. She then slices through her finger, which she blames on him distracting her.

A nurse asks Maggie if she's been sexually active within the last six months. She says she has in the last 48 hours, very active. The nurse says the doctor will be in shortly and Maggie asks her to run a full STI panel, including HIV and Hepatitis B. Andrew comes in and they are surprised to see each other. He's there to examine her, but offers to find her another doctor, which she wants.

Alex bandages Meredith's finger. Meredith starts to tells him about Penny, but he says that she seems nice. He hasn't talked to her much, but she's into Callie. Callie then comes in and says she has to leave to check on a patient because her fellow is an idiot. Penny is planning to leave with Callie, but Callie insists that she stay because it'll only take a minute. Callie tells Alex to get Penny another drink. They leave and Callie comes back and asks Meredith to keep an eye on Penny to make sure she's having fun.

Penny puts a chair at the table and tries to talk to Meredith. Meredith says Penny can make small talk with anybody else in the house, but not her. Callie will come back and they will have a meal, then she will leave and Meredith will never have to see her again. Meredith sees Bailey and introduces them. Bailey says her name sounds familiar, but can't figure out why. Bailey wonders where Callie is.

In the ER, Callie tells Owen she can't figure out why Penny was so nervous. She and Arizona have a lot in common and they talked and talked. Everybody loved Penny. She asks Owen if he's heading over. Callie says the consult will only take 10-20 minutes, which will give him time to change, so they should drive over together. Owen asks what's wrong with what he's wearing. She says nothing, it looks good on him, but asks if he knows that Amelia's there.

April is still cooking. Arizona says she's amazing, that she made order from chaos. April takes away the knife Arizona was brandishing. Alex asks if he can help. April says he can mince the garlic, but he doesn't know what that means. Jo is chopping. Alex asks if she's having fun. She says she's not, but Alex asks if she noticed that Meredith's barely speaking to anyone before walking away. April critiques Jo's chopping and demotes her to trash duty. Arizona tells her Jackson's an idiot because she's a Penny. Callie has a Penny and Jackson had a Penny but threw it away. Why doesn't she have a Penny? April asks her to stop and she apologizes. April says the party sucks and takes a sip of Arizona's drink.

Alex lets Isaac in and he says Jo didn't say how much cheese to get, so he got a bunch, even though it's expensive. He tries to flirt with her and then scolds himself for it as she sends him to the kitchen while she drags the trash out. Stephanie sees Jo and says she'll get out of her way, but Jo wants to talk. Stephanie asks if she's wondering how she's even there, since Jo went behind her back and told them that she'd lied?

Alex and Jackson make a deal so Alex can go get tacos for them. Amelia comes in and asks them how much the party sucks on a scale of one to ten. Alex says one or ten, depending on which one means it sucks the most. Alex is only there for the free food and there's no food. Jackson points out that the guests are making the food and asks if she even wanted to have the party. Penny comes in to grab her coat. She wants to leave. Amelia says she should stay because they're nice people and she just needs to get to know them. Meredith comes in and says dinner's ready, so Amelia says she's trapped.

At the table, Amelia tells Penny to sit next to her because everyone else has heard all of her jokes. Isaac puts something on the table. Jo tries to dismiss him, but Arizona tells him to pull up a chair. There's not a chair to pull up, so he sits on a toy horse. Jackson asks where Callie is. Jo is shocked that Penny just left her there. Penny says Callie said she'd be right back, but they all know how night call go, so she might be asking one of them for a ride home. Arizona says she'll take her home herself if Callie doesn't come back soon. She says she's being nice. Bailey points out that she's drunk, which she's never seen before, but she says she likes it. Arizona likes it, too. April asks Penny what she does. Penny says she's a surgery resident. April asks where she works. Penny says she's between gigs. The hospital where she was working was closed down, so she was re-matched. Hearing that Penny's full name is Penelope, Bailey makes the connection. She knows Penny's name because she's on Bailey's calendar. They have a meeting. She's their new transfer resident. They all congratulate and welcome her, but Meredith asks if she's kidding. Amelia asks where she was working before. Penny tries to dodge the question, but Meredith tells them she was at Dillard Medical Center, where Derek died. Perfect Penny killed her husband. Meredith tries to get them to start eating again, but then excuses herself from the table.

Everyone sits in silence until Amelia asks what Meredith said. Penny tries to explain, but can't find the words. Alex dismisses himself to check on Meredith. Penny says she was one of Derek's doctors. Amelia tells Penny Derek was her brother. Callie and Owen then come in laughing. They're happy they didn't miss dinner. Seeing how quiet everyone else is, Callie asks what's going on. Arizona says Penny's coming to work for them. Callie thought they were going to wait to tell everyone. Amelia then says Penny killed Derek. Amelia wants Penny to tell her what happened.

Andrew comes in and says it'll be another 45 minutes, but he's sure it's just a UTI. Her gives her pyridium and cranberry juice. She wants to wait for the labs to confirm. She thinks it could be an STI. He wonders who she thinks he is. He says he could assume she gave him something, but he doesn't. She apologizes. He starts drinking the cranberry juice. When she points out it was for her, he hands it over. She wipes off the brim before taking a sip.

Callie sits in Meredith's vacant seat and asks Penny what they're talking about. Penny says she tried to tell Callie when they got there. Amelia again asks Penny to tell them what happened. Callie says she doesn't have to. Jackson suggests they give Penny and Callie some space, but Amelia says again she wants to hear what happened, if Penny made a mistake. Penny starts to explain. She says it sounds like she's making excuses. Penny apologizes to Callie and says she should go. Amelia wants to hear the rest. Callie tries to stop her, but Amelia asks if she knows what his last words were. Callie bangs her fist on the table and says that's enough. Amelia tells them to get her out of her house and walks away.

Alex asks Meredith what he wants her to do. Amelia comes in and says they need to have a board meeting to fire Penny. She asks Meredith if they're going to take care of it. Meredith doesn't want to talk about it. Amelia asks why Meredith didn't tell her. She welcomed Penny into their home. She hugged her. Meredith says she didn't do anything to Amelia. She says she lost her husband and the father of her children. She doesn't get to fall apart because she has three kids. She tells Amelia to get out of her room. She then tells Owen to get her out before she kills her. Owen leads Amelia out of the room.

Callie comes outside to find Penny. Penny's on the phone and asks for the address for a cab. Callie asks again why Penny didn't tell her. Penny tells the cab company she'll call back and says she didn't know if she knew Derek. Callie says Derek was her friend. He was all their friend. Penny says he was the worst night of her life. Callie goes back inside.

Owen asks if he should go find Webber or find a meeting. Amelia says they can't do that to her. Owen says no one's done anything to her. It's been a terrible night for a lot of people. Amelia asks how he's always so calm and reasonable, but she's not like that. He says he's not perfect. He says when he heard the plane had crashed, his first thought was that she was dead and he was relieved because he always knew one day she'd leave him and this way, she was dead and they'd stay frozen in time forever. She'd be gone, but it wouldn't be so hard. He hated himself for thinking it. He says he makes things harder than they need to be. He makes things hard for them. Amelia says it's the worst thing she's ever heard. She advises him never to do drugs because he won't be able to stop. She grabs his hand and he pulls her into him and holds her and says they're not perfect, but so what?

Stephanie asks if anyone's seen Penny. April and Jackson are doing dishes and he says he thinks she was waiting for a cab. Arizona is eating dessert right out of the dish and asks if she should do anything because Callie's her ex. April says she feels bad for Penny because she was ambushed. She's a resident. It could have been any of them. April says it was her. She missed an airway and killed someone's mom. She still says a prayer for her family every night. Jackson says those things are never just one person's fault. April says some things are. Some things, you screw up and you can't take them back and you pay for them for the rest of the night. April says those are the last of the dishes and she needs to get Arizona home. Jackson says she shouldn't drive either, but April says Isaac's going to drive them. Jackson says the dinner was excellent and thanks April. April takes Arizona and leads her out.

Jo finds Stephanie and says she shouldn't have ratted her out to Webber and Shepherd. She knows now that Stephanie wasn't lying. She apologizes. Stephanie says it's okay and she gets it. She's sorry it happened to. Jo says Alex is ignoring her and they agree that he's being a jerk.

Alex puts a tequila bottle in front of Meredith. They're on the floor of her bedroom. Meredith says he can go, but he asks what she'll do if he leaves. She points to the bottle. He opens it and takes a drink. She then takes the bottle and takes a drink. She says Penny's a person now. Callie knocks on the door. She opens it and asks Meredith if she's okay. Meredith says she's great and closes the door with her foot. Alex hands her the bottle to take another drink.

Maggie says her good relationships all started as friends, then became more, before dying. Andrew says dating sucks. His problem is that the first dates usually end up in sex, but he doesn't get a lot of second dates because women assume he's moved on. Maggie gets it because of his hair. It's very confident and swoopy. She says last night was clearly not his first time at bat because he knocked it out of the park. He says she pitched a perfect game and admits he doesn't know anything about baseball. She asks how long it takes to get tests results. He tells her to go and he'll send her the results. If it'll make her feel better, she can just ask if she wants to know anything about his history. He'll tell her anything. She says she's not sure she wants to know, but he says the alternative is harder, just trusting him. She sends him out so she can change. As he leaves, he points out that there's nothing he hasn't already seen, so she throws an empty bottle at him.

Stephanie tells Jo to ditch Alex and she'll give Jo a ride. Jo says she doesn't think Alex would notice. Stephanie's glad they talked. Today sucked, but she's glad they didn't let it get in the way of their friendship. Jo says it makes sense now. Stephanie was sick and Jo had a crappy childhood. They had to work harder to get where they were. Stephanie says Jo just can't wrap her mind around the idea that Stephanie might just be better at being a doctor than she is, stronger, smarter, and more savvy. She needs a motive behind Stephanie being better than she is. Stephanie tells her to stop trying to make them even because they're not even. She needs to deal with her jealousy and her shortcomings. They're on her. Stephanie leaves. As Stephanie goes out, Maggie comes in and asks how dinner was. She has to pee again.

Stephanie walks past Callie, who asks her if she's seen Penny. She hasn't. Jackson comes out and Callie asks him about Penny. Penny's stuff is on the porch, but Jackson figured she'd left. Callie wonders what the odds are that she's the one person ... she doesn't know how to shut her feelings off. She doesn't know if she wants to. Jackson's not sure she can even if she wants to. Jackson tells her to get home safe and leaves.

Meredith and Alex come downstairs. Alex asks if she wants him to stay. Jo's waiting in the car, so she tells him to go. Once he's gone, she takes a breath. She walks toward the kitchen just as Penny comes out of the bathroom. Penny says she's leaving. She called a cab. She apologizes, saying she wouldn't have come if she had known. She says she'll file a request in the morning to be re-matched again and Meredith will never have to see her again. Meredith goes to go upstairs, but Penny stops her, saying she didn't forget about Derek. She never will. Meredith said that Derek was her One and she thinks about that night, about Derek, every day. She goes to leave, but Meredith says she'll see her on Monday and not to be late.

Main Cast

 * Ellen Pompeo as Dr. Meredith Grey
 * Justin Chambers as Dr. Alex Karev
 * Chandra Wilson as Dr. Miranda Bailey
 * James Pickens, Jr. as Dr. Richard Webber (credit only)
 * Sara Ramírez as Dr. Callie Torres
 * Kevin McKidd as Dr. Owen Hunt
 * Jessica Capshaw as Dr. Arizona Robbins
 * Sarah Drew as Dr. April Kepner
 * Jesse Williams as Dr. Jackson Avery
 * Caterina Scorsone as Dr. Amelia Shepherd
 * Camilla Luddington as Dr. Jo Wilson
 * Jerrika Hinton as Dr. Stephanie Edwards
 * Kelly McCreary as Dr. Maggie Pierce
 * Jason George as Dr. Ben Warren (credit only)

Guest Stars

 * Giacomo Gianniotti as Dr. Andrew DeLuca
 * Joe Adler as Dr. Isaac Cross
 * Samantha Sloyan as Dr. Penelope Blake

Co-Starring

 * June Carryl as Nurse

Maggie Pierce

 * Diagnosis:
 * Urinary tract infection


 * Doctors:
 * Andrew DeLuca (surgical intern)


 * Treatment:
 * Pyridium

Maggie had a frequent urge to urinate, so she suspected she had a UTI. She went to the hospital to get tests to confirm and also asked the nurse to run a full STD panel, including HIV and Hepatitis B. Andrew then came in because OB was understaffed, so he was told to go exam her. He came back with the medication for her and cranberry, saying it was a UTI, but she wanted to wait for labs because she wasn't sure it wasn't an STI. Despite this, she took the cranberry juice and started drinking it. Andrew eventually told her to go ahead and leave and he'd send her the results.

Callie's Patient

 * Diagnosis:
 * Posterior shoulder dislocation


 * Doctors:
 * Callie Torres (orthopedic surgeon)
 * Unnamed fellow


 * Treatment:

Callie got paged back to the hospital to attend to a patient with a posterior shoulder dislocation. She tried to talk the fellow through it over the phone, but it didn't work, so she had to go in to check on the patient herself.

Meredith Grey

 * Diagnosis:
 * Laceration


 * Doctors:
 * Alex Karev (peds surgeon)


 * Treatment:
 * Bandage

Meredith cut her finger while slicing apples. Alex put a bandage on the wound.

Notes and Trivia

 * This episode's title originated from the song , originally sung by Black Uhuru.
 * This episode scored 9.00 million viewers.
 * The table read for this episode took place on September 2, 2015.
 * This episode contains Jessica Capshaw's favorite scene of the season so far.