Docs Cooper, Pete, and Violet pay a nighttime visit to Addison's house because they have a surprise for Sam: they ordered him a stripper! They're all planning to watch the fun from Addy's big windows, but then Naomi shows up and catches them watching, and the next morning, Naomi's too jealous to acknowledge Sam, who is amused by this reaction.
Cooper meets with the O'Briens, whose baby, Emily, is a few months old and suffering from an unnamed ailment. Dad O'Brien seems to have no connection with Emily, which upsets caring pediatrician Cooper. Meanwhile, Violet receives a delivery: an expensive bicycle she bought some time ago for her now-married ex-boyfriend, Alan.
Sam makes a house call to check on "Dave," a patient who's been complaining of nausea (and drinking too much), and finds him passed out on the floor. Dave's vacant elderly mother and Stevie, his teenage son, are ill-prepared to care for themselves, so Sam sends both in the ambulance with Dave. Later, Sam stops by St. Ambrose (the hospital) and learns that Dave has been discharged by Charlotte, who protests to Sam that Dave's mother promised to look after him. Sam is not comforted by this.
Addison helps Cooper interpret and share the results of baby Emily's blood tests: She has a rare genetic disease that will likely kill her by age 5. Mom O'Brien is naturally distraught; Dad is still unnaturally detached. Genetic tests turn up something even more difficult to explain: Mr. and Mrs. O'Brien are not Emily's parents. Baby Emily was delivered at St. Ambrose, so Addison and Naomi have to go talk tough to Charlotte to get their nursery records and figure out what happened. Turns out the only other eligible baby belongs to a couple that Naomi had helped conceive. Back to Oceanside we go. Tests confirm the babies were switched. Violet delivers the news to the O'Briens, who aren't thrilled; Naomi informs her patients, the Stinsons, and an angry Mr. S. demands his money back.
Meanwhile, Ginger the stripper shows up at Oceanside to be treated by Pete, who spends the rest of the day working on her. Addison finds this inconsiderate of Naomi's feelings, and she lets him know it. He offers/threatens to kiss her again.
Dave's mother shows up at Oceanside with Stevie, who is now doubled over and puking just like his dad was earlier. Tests show Stevie was poisoned by some kind of mushroom interacting with alcohol, and Sam discovers that Grandma has been intentionally poisoning Dave to punish him for drinking. She's trying to protect her family, she insists. So Sam holds a mini-intervention -- when he can't convince Dave to seek treatment for his alcoholism, he tells him that he has developed a sudden and severe allergy to alcohol, and enlists Grandma's help in keeping him away from it in the future. Dave seems to fall for this.
After poring over records with Charlotte, Addison figures out that it must have been a parent who switched the babies at St. Ambrose. Mr. Stinson confesses -- he wanted a healthy baby, since he guessed he'd never have another. The police take him away. Mrs. Stinson is appalled. She follows her mothering instinct and accepts sick baby Emily, turning over her own healthy baby to Mrs. O'Brien. They share mothering tips for the infants they've raised. Disaffected Dad looks on, crying at last. Even Charlotte cries.
Pete complains about the hard day he's had treating Ginger, and Addison notes that her day was worse. He informs her that he likes his women "natural" and mature (unlike Ginger), and then notes, for good measure, that Addy has no one to take care of her. Meanwhile, Naomi is still upset about the prospect of Sam dating Ginger, after being married to a catch like herself. Sam promises that the first woman he dates will be even better than Naomi, which she thinks is sweet.
Cooper, sad from his long day with the sick baby, shows up at Violet's to find her hacking the bike to pieces. She confesses that she tried to give it to Alan, but found his wife had already bought him one. They cuddle and plot further violence to the bike. Addison and Naomi sit on the beach outside Addy's house, looking up at Sam and his dog. Naomi wants to keep watching for a while, so they do.
It's nighttime in L.A, and Addison's at home, sipping wine. Because it's dark out, and because she's at home, she's also wondering why she's surrounded by her Oceanside colleagues. "What are you people doing in my house?" she asks Cooper, Pete, and Violet as they run around switching off her lights. (The closed-captioning transcribes this question as "What are you people doing in my hoe?" which must have been perplexing for the hard of hearing.) Cooper and Pete explain that they have a surprise for Sam. Pete pretends to be ashamed that he's involved. Addison doesn't see why this "surprise for Sam" should require everyone to be at her house -- maybe the gang got confused, since the houses are practically conjoined? -- but she wishes they'd leave, since BFF Naomi is on her way over. Cooper is dismayed. Naomi will ruin the surprise! Now Violet wants to know what kind of "surprise" this is, and when she hears, "One named Ginger," her sense of decency briefly surfaces, and she scoffs, "I'm outta here." Then Cooper announces that Ginger is about to appear, and Violet scurries to the window to watch the fun unfold.
Sam is hard at work on a Sudoku puzzle (cheered on by his comically small dog) when Ginger rings the doorbell.
At Addison's, Violet wonders how Cooper knew where to find a stripper. Violet, this is Cooper, your best friend. Apparently you've never met. Cooper corrects her choice of words; Ginger is "an entertainer." Behind them, Addison protests that Sam, unlike Cooper, is "not interested in--" but Pete cuts her off: "I think Sam is." And they all watch Sam stare at Ginger's bumping-and-grinding rear end like he's trying to memorize it. Addison's lights flick on: Naomi has walked in, just in time to hear Addison say, "Sam and a stripper -- who knew?" And man, does Naomi look grumpy. Cooper tries to blame Addison, Pete closes a curtain, and nobody's watching when Sam, still captivated by Ginger's ass, says, "You have something." He's referring not to her flair for erotic dance, but rather to the nasty-looking rash spreading across her right buttock. Ick.
Dawn spreads out her time-lapsed rosy fingers over L.A., and the docs gather in Oceanside's conference room. Sam finds Cooper alone and demands, "What were you thinking?!" Pete is still pretending to be above all this. Cooper just wants the details; he's clearly familiar with Ginger's "entertainment" techniques, and he wonders what sort of entertainment she provided for Sam. When the ladies walk in, he pretends to be discussing a medical case, but they are not fooled. Down to today's business: Sam announces that "Dave Walker" called, complaining of headache and nausea. Cooper says he heard that Dave's wife left him (in the Oceanside patient-gossip chat room, I guess), and Sam confirms that Dave, who lives with his mother and his son, is "drinking again" as a result. So Sam's planning to "go check him out." Addison is surprised to hear that Sam does house calls. Pete corrects her: "We all do house calls." She shoots him a look, and he's all, "What? It's not my fault you didn't ask any questions before accepting this job."
Cooper sets up his storyline: the O'Briens are bringing in their nine-month-old baby girl, who's been sick since birth. Violet helpfully pipes up with what she remembers from the gossip chat room: is this the dad who's totally disconnected from his baby? Cooper confirms that it is, and that he's tried to get Dad O'Brien to see Violet, but with no success. Addison offers assistance with the case. Pete says, "Wanna help me?," and it's possible that he didn't mean it in a smarmy way, but Addison shoots him a disgusted look anyway. "What?" asks Pete. Naomi speaks up: "Anything else?" Sam starts talking about some patients he'll be seeing next week, but she talks over him: "Nobody? Super." She leaves. Cooper pretends to have more medical questions until Naomi's out of earshot, and then goes back to asking for details about Ginger's performance. Addison scolds everyone for not thinking of Naomi's feelings, and goes after Naomi. Sam is confused: "Wait, do they know?" He interrupts himself with the best "gasp" in the history of television -- seriously, you should watch the episode just for this one line -- and asks, "Does Naomi know?" Cooper yammers on about Ginger. Sam hangs his head.