Upon realizing that Owen and Amelia have been seeing each other behind her back, Meredith comes down hard on her sister-in-law causing Amelia to rethink things. Meanwhile, Catherine springs into action when a man is brought into the hospital after his wife seeks revenge on his cheating ways.
- Meredith and Derek are back in the swing of things in bed, but the baby's crying and it's time to change diapers and get to work. He's preparing to fly back to D.C. and resign, and says he'll be home before Meredith knows it. Amelia comes over, and Hunt follows her in to return her cell phone. Derek smiles knowingly and Meredith is surprised to learn that Amelia and Hunt are hooking up.
Pierce is worried about Ethan not calling or texting, or noticing her at the hospital. She's pestering Alex trying to figure out what her problem might be.
Meredith starts grilling Amelia about her status with Hunt because she promised Cristina she'd keep an eye on him. Amelia seems a little annoyed by this, but takes it out on Stephanie and tells her to stop bugging her.
Marissa, a junior golfer, has a misalignment in her spine. She's obsessed with not having her golf game affected.
A man and woman come into the E.R. with blood all over them and the man screaming in pain. The woman keeps trying to hand Bailey a paper bag but Bailey is trying to treat her wounds. The man is bleeding more and we all soon learn that his wife cut off his penis. April suggests to Webber that they call in Catherine Avery, who specializes in such cases, but Webber insists that their own urologist can handle it. Bailey learns that the man is Thomas Archibald, the city's hot chef, and gets the scoop on the fact that he has apparently been having an affair with the sous chef who came in with him. Meanwhile, Stephanie runs through the hospital to bring the severed penis to Jackson, providing an opportunity for a ton of double entendres.
Stephanie, who's worried that Amelia isn't going to let her work in neuro anymore, asks Webber if he always wanted to do general surgery. He recounts the moment when he realized it.
Amelia and Callie are bickering about what the best approach is to help Marissa the golfer. Hunt overhears the conversation and sides with Amelia.
Catherine Avery shows up and April gives her a big hug on the helicopter pad. Catherine gets started on Thomas. Webber walks in and is surprised to see Catherine. He's annoyed that April called her after he told her not to.
Amelia tells Marissa she's going to do everything she can to get her back on the golf course, but we know that Amelia's approach was less focused on Marissa's physical movement and more in favor of her longterm health.
Pierce gets some X-rays from Ethan and unloads on him about not getting back in touch after their date. He says nothing while she talks, then he finally tells her that she never shuts up. He tells her that it wasn't even a date, it was a monologue, then she paid. She's speechless.
Amelia runs into trouble in surgery and tells Ben to find Callie because her approach is the one Amelia needs to do.
In the gallery, Arizona, Meredith, Bailey and Callie talk about how mad they'd have to be to cut a man's penis off. It turns into Arizona and Callie actually somewhat light-heartedly talking about Arizona's cheating and Callie's cutting off of Arizona's leg.
Ben plays peacemaker in Marissa's surgery while Amelia and Callie continue to argue about what should be done first. He forces them to agree on the approach.
Callie and Amelia report to Marissa's mother that her daughter's spinal issue was more serious than they thought, and that she might be able to walk again with therapy. The mother is furious and tells them that they were supposed to be as excellent as her daughter was at golf. Callie tries to reassure Amelia, but Amelia is convinced that they should have taken Callie's approach from the start. Amelia then goes off on Hunt because she thinks he only sided with her because they're sleeping together. She says their relationship is a mistake.
In surgery, Alex suddenly starts trying to assure Pierce that there's nothing wrong with her.
Thomas' wife shows up and he starts apologizing to her. Apparently they had a deal that he could sleep with waitresses and hostesses, and his wife was upset that he'd slept with his sous chef. They kiss and apparently make up, much to Catherine and Stephanie's surprise.
Webber confronts April about calling Catherine, and April says she won't allow his personal issues to get in the way of her patient's wellbeing.
Pierce, meanwhile, apologizes to Ethan for talking too much during their date, saying she inappropriate "brought the thunder." He hears her out and says that next time he'll "bring the thunder."
Amelia goes to Meredith's house and tells her to back off and stay out of her relationship business. She says Meredith doesn't know anything about her or what she's been through. Meredith says nothing.
Stephanie is excited because Catherine told her she's "above average" and thinks urology could be her speciality. Suddenly, there's a scream from Thomas' room and the sous chef runs out of it. She cut his penis off this time. Stephanie chases her.
Stephanie chases her into the women's bathroom, where the sous chef threatens to flush it down the toilet. She cries as she tells Stephanie how Thomas had said he was going to leave his wife and they were going to start another restaurant together, but he took her back even after she cut off his penis. Stephanie manages to convince her to hand it over.
Catherine tells Stephanie that she's doing great and says she hopes Stephanie will consider a urology fellowship with her in Boston. Webber, meanwhile, makes up with Catherine and they kiss and all is well.
Callie gives Marissa a pep talk and assures her that she'll find something else to love as much as she loved golf.
Ben and Jo are impressed with Stephanie's story about how she got the penis back and Catherine invited her to Boston, but Stephanie said all she could think when she was holding the severed penis in her hand was that it was gross and that's not what she wants to do.
Alex smiles as he watches Pierce and Ethan leave the hospital together, then goes to get some tots with Jo in the cafeteria.
Hunt goes to Amelia and asks her what's really going on because he wants to understand. Amelia gets a phone call, but it was actually for Derek. Meredith takes it and is surprised to learn it's the White House. He missed his meeting.