It's Valentine's Day, and Derek and Hunt are dragging out their ladies the only way they know how -- on a double date. The girls are absolutely thrilled when they all get pages because of a massive medical emergency: a local restaurant's roof has collapsed and because it was Valentine's Day, it was full. Everyone is called back to the hospital to work, and it seems that Arizona and Callie were the only ones smart enough to go on an early date that day. That means that they are loved up and giggly, so when they notice that hot anesthesiologist Dr. Warren is flirting with Bailey they begin to tease her and then realize from her reaction that she might actually be interested. Arizona hangs out in Bailey's surgery with the excuse that she is observing, but instead just makes a lot of coy comments to insure that Warren realizes Bailey likes him, despite turning down his dinner invitation earlier. Bailey is completely annoyed but later admits to Dr. W. that she does like him and they make plans to go to dinner. Go Bailey!!
Callie, meanwhile, gets roped into helping Sloan Sloan, who is back from LA and acting all shifty as she asks for an ultrasound. It turns out she wants to give the baby up for adoption and is trying to do it without Mark finding out, on account of his being so gung-ho for the baby. When Callie finally forces her to admit what she's doing, Mark offers to adopt the baby himself, and Callie is so moved by his sincerity that she offers to help him raise it. They convince Sloan to at least think about this offer, but that evening Callie finds Sloan trying to sneak out of town. Sloan finally makes her see that she needs to get a clean break from the baby, which she would never have if Mark was the one raising him, and so Callie gives her some money and makes her promise to take care of herself before sending her off, and then deals with the heartbreaking task of telling Mark what happened.
Lexie, meanwhile, tries to make a change to get over Mark and goes blonde, though based on where the story goes I guess she's also maybe trying to get his attention? I'm not sure, the getting from a to b there was a bit sloppy. I must admit that she looks way better than I thought when I heard that this was going to happen, but while Mark flirts with her before he realizes who it is, the new hair color doesn't do much for her and Avery convinces her that if she wants to get noticed, she needs to do something major. One of the victims from the restaurant accident is a dishwasher whose arm is severed, and while Lexie is able to clean up the arm enough for it to be viable, his remaining stump needs a few days to heal. She has the idea to attach his arm to his leg so that the blood flow will keep it viable until his stump heals enough to reattach the arm a few days later and convinces Hunt and Mark to try it. The poor dishwasher is completely freaked out when he wakes up and sees his new appendage, as he is someone who likes to keep to himself and draw no notice, but now he's the guy with an arm sticking out of his thigh. Lexie, however, convinces him that he's special, not different, and that that is a good thing -- then she celebrates by hooking up with Alex again.
Alex needs some cheering up after his evening -- his patient is a veteran head waiter from the restaurant who has been in love with one of his customers for the last fifteen years. He bribes Alex to be put in the same room as the woman while her husband is in surgery with a giant piece of glass sticking out from his chest. Meredith is the woman's doctor, and she and Alex wind up betting the bribe money on whether or not the waiter will spill how he really feels. Alex thinks that he will, but Meredith thinks that he won't. Alex kind of wins because when the waiter admits to everything, the woman was only faking sleep and heard it all, but later she admits to Meredith that while he thinks she is unhappy in her marriage because they don't talk a lot during dinner, she's actually just comfortable and loves her husband -- and she knew that he was in love with her but since he never said anything before, she made a choice and that choice was the man she wound up marrying. While Bailey winds up saving the husband after a tricky surgery, the waiter friend turns out to have a brain bleed that was undetectable, and he dies -- and even though Mere's patient made her choice, she's still devastated and neither Mere nor Alex really want to claim the bet money after all that. While Alex winds up comforting himself with hot blonde Lexie, Meredith steps up and joins Derek at a trustee brunch which she had been planning to avoid, but she realizes that she is a wife and that her husband needs her.
Finally, Hunt spends the whole evening trying to avoid Teddy, until she confronts him and yells at him that she misses her best friend who she could just talk to. He admits that he misses her too, but feels like he is cheating on Cristina when he talks to her so they can't. Teddy finally comes up with a solution to confront Hunt with Cristina there, and she tells him that she's basically taking it all back so that she can have her friend back, because she has an awesome job she loves and a great new house and an amazing student in Cristina and doesn't want to not have Hunt just because of what she said. Cristina seems happy with this, especially because Teddy puts her right onto a cardio surgery, and while Hunt tells Teddy she can't unring this bell, she happily tells him that she knows it but she's still going to try.
Izzie is gone, Sloan leaves for good, and characters are acting mature and displaying personal growth? Pinch me, I must be dreaming!
Valentine's Day is for jazzy, funny music! Over evening shots of Seattle, Mere tells us, "The surgical scalpel is made of sterilized, carbonized, stainless steel. This is a vast improvement over the first scalpel, which was pretty much a sharp stick. Medicine is constantly reinventing itself. That means surgeons have to keep reinventing themselves, too." Derek has reinvented his vehicle -- he's driving himself, Mere, Hunt and Cristina on a Valentine's double date in a Porsche Cayenne which feels about as far a cry from his old jeep as he could get. I guess he figured this was more Chiefly. The girls are not into this outing at all, and when Hunt dares to suggest that there's more to life than the hospital Cristina shuts him down. Mere then also corrects Derek when he suggests that this is romantic. All four of them perk up as an ambulance drives by, sirens blaring. Mere VOs: "There's constant pressure to adapt to changes. It can be a painful process. But without it, you'll find yourself moving backwards instead of forwards." When a whole line of ambulances follows the first, the guys insist to their drooling ladies that if it's important, they will be paged. A second later, their pagers erupt and the girls cheer as they turn around to head back to the hospital.
Callie is wiping the entire surgical board and explains to Bailey and Arizona that the roof of Grandinetti's (yes, let's spell it like that, shall we? It sounds right for a fictional Italian restaurant...) (yup, closed captions still only working some of the time) collapsed, and as it was a romantic restaurant and it's V-Day, it was packed. As the three walk and Callie gripes about how she knew this would happen, Arizona cheerfully reminds her that this is why they went to dinner early and exchanged gifts. In unison, she and Callie pull out silver necklaces and show them off to Bailey in a fit of delighted giggles. Bailey dryly informs them that she is squealing with joy. She doesn't put much stock in this fake holiday, and I tend to agree -- you're either single and made to feel kind of like a loser, or you're in a couple and face a ton of pressure to do the perfect thing that usually involves dinner at an overcrowded restaurant. And in this case then the roof of said overcrowded restaurant goes and collapses, which really puts a damper on a celebration of your love. Hot Dr. Warren walks up and tells Bailey he's sorry that their surgery was pushed, and then asks her to dinner. She shuts him right down saying she has surgery most nights, and so he stutters that maybe he'll see her in the OR. She doesn't answer, but when she and the girls get in the elevator Callie laughs as she comes to the realization that Bailey likes him. Bailey bites her lip and tries not to laugh while they giggle away behind her, and she finally gets a hold enough to demand that they stop the girl talk because she's busy. They manage it for a second before dissolving into giggles again while Bailey shakes her head.