A successful gene experimentation leaves Sheldon excited to procreate with Amy, and he pulls out all stops to get her on board. Meanwhile, Raj is reluctant to reveal what the new woman in his life does for a living.
Sheldon is sitting in Amy's lab lamenting how much the skin tissue sample she is about to take from him is going to hurt. Amy wants to synthesize a neural network using their joint skin cells. Sheldon is willing to do it for science though the alcohol swap is very cold. Amy gives him a count of three before he takes it. Three. Two. Swab! Sheldon doesn't even feel it, but does make her say three because of his need for closure.Raj is in the telescope lab eating Funyuns and looking for extraterrestrial planets. Isabella the maintenance worker comes in. Raj finds a gravitational wobble that could be an extra-solar planets that could have life on it and could be named after him. Isabella wonders if there is life, maybe it already has a name. Raj helps her with the trash and they do stare at each other for a moment and then say goodbye. While Amy is checking their brain cells, Sheldon pushes her aside and all he sees is his own eyelashes. Amy then checks and finds astrocytes which means they have grown a primitive neural network. Sheldon then finds himself with a profound sense of creation since they used his DNA. Not unlike when he made sea monkeys. Since it was also using Amy's DNA, he redefines their creation as we-monkeys. They then start to test it to light and sound to see how it reacts.
The gang is around the table in Apartment 4A. Howard figures the order was screwed up since they got steamed broccoli which was for Raj. Penny is sure that he must be seeing someone since he has switched to broccoli. Finally he admits that he meet a woman in telescope room named Isabella. Leonard figures that she is an astronomer and then Raj doesn't correct him.
Bernadette is discussing their DNA experiment at their place (4B). She can't believe that one can turn skin cells into functioning brain cells. Amy counters that she turned Sheldon into a functioning boyfriend. Sheldon is showing Bernie pictures of their creation. They have provide that it reacts faster than any other network made by Amy. According to Bernadette, her baby is now facing down getting ready for birth. She gets uptight when Sheldon compares their growing neural creation with her gestating human child. Sheldon agrees to think of both of them special in their own way, though they didn't have to have sex with Howard to have theirs.
Raj is helping Isabella clean the men's room calling it fun. He also mentions that he had a cleaning lady and other servants when he was growing up. Raj finds out that she is unmarried and has a 19 year-old son at UCLA studying law. She appreciates the interest, but she works two jobs and has no time for dating. She tells him "Good night", though Raj while leaving says that he still thinks that there is something going on between them.
Amy and Sheldon are very happy with their results since their little network is processing more information than most. He wants to go onto step two. Amy says that would be to try replicate their results again. No. Sheldon wants them to have a baby. Amy asks what he is talking about? Sheldon points out that their DNA combination is truly exceptional and that it might be the next step in mankind's evolution. Amy is not ready to have a baby, even though Sheldon insists that her menstrual cycle is just right for it. Sheldon then leans over and starts wiggling his bottom at her. Amy gets disgusted and leaves.Isabella comes into the telescope room and has found that Raj has made them dinner since she was too busy to go out. He even cleaned up the next offices so that she could take a break. He made what he claimed was food from her homeland. Cuban food? Raj then wonders if they had Mexican food in Cuba. Amy is discussing Sheldon's need for making a baby with Leonard and Penny. Penny wonders if he wanted to make the baby out of Lego. Penny asks if they would have a super-intelligent child? That was possible, but not guaranteed. Sheldon's father once picked a fight with a cactus, but that didn't include his extraterrestrial parents that sent him to earth. Reaching the top of the stairs, Amy finds a path of rose petals going into her apartment. "Oh, man!" she exclaims. Leonard and Penny to have fun with whatever nightmare is behind door number two. Amy finds the lights low, candlelight, cool jazz playing and Sheldon dressed up with his hair slicked down drinking brandy from a snifter. Sheldon offers her a brandy and Amy declines. Being himself for once, Sheldon replies that it is just as well since it's disgusting. Amy tells him to stop trying to seduce her and then leaves. Sheldon calls to her that he doesn't know how to open the oysters.
Raj is now having dinner with Isabella. They are talking about when they first came to America. She mentions that she has some time off on Sunday as Howard comes in. He asks if she was the astronomer that Raj met. Isabella is not happy and leaves because she is not going to waste her time with someone who is embarrassed by her. Raj runs after her to apologize and he tells her embarrassing things about him. Finally she says that he can take her out to a nice place to eat on Sunday night and it can be Pakistani food if he likes. He says he's Indian, to which Isabella says now he knows what it's like to be stereotyped.
Amy is talking to the Hofstadters. Penny wonders how much she was turned on. Amy said it felt like being hit on by Rat Pack Pee Wee Herman, meaning she wasn't. Sheldon comes in and starts to flamenco dance to Amy, the world's most sexiest dance. Amy calls Sheldon ridiculous and then leaves. Leaning up against the wall outside of 4A, Amy is obviously turned on and exclaims, "That was a close one."
- Guest starring:
- Teleplay: Steven Molaro, Maria Ferrari & Tara Hernandez
- Story: Chuck Lorre, Steve Holland & Saladin K. Patterson
- Title Reference: Sheldon and Amy mix their DNA and incubate some brain cells.
- Taping date: October 25, 2016
- This episode was watched by 14.22 million people with a rating of 3.4 (adults 18-49).
- Total viewers including DVR users 19.79 million.
- The Big Bang Theory was ranked #17 for the week ending 13 November, 2016.
- This episode aired in Canada on November 10, 2016.
- Chuck Lorre's vanity card 
- Episode transcript 
- Ashley Bissette Sumerel at TV Fanatic - Leave it Sheldon to choose the most logical reason, and most logical time (he's been tracking Amy's cycle!) to try and have a baby. It's Amy who isn't quite on board with that idea yet, even though Sheldon is doing his best to seduce her. I'd say this was out of character, but Sheldon's inspiration for the idea is realizing that he and Amy could have incredibly intelligent offspring. All thanks to some skin cells. I have to admit, that's something I'd enjoy seeing down the road, but I'm more interested in the idea that, for once, it's Sheldon who wants to take a new step, and Amy is the one who isn't ready. 
- IMDb user reviews 
- Bernadette only appears in one scene in this episode, not sharing scenes with Leonard, Penny, Howard or Raj, just with Amy and Sheldon in their new apartment.
- Raj has a new love interest: Isabella.
- This episode once again involves everyone referring to Sheldon as some kind of extra-terrestrial.
- Third episode after "The Apology Insufficiency" and "The Parking Spot Escalation" where Howard sits on Sheldon's Spot, this time without him to see it.
- For the first time in 4 years, Raj mentions his sister Priya -not saying her name- when Raj tells Isabella that his sister is a lawyer after Isabella tells Raj that her 19-year-old son is studying to be a lawyer. The last time Priya was mentioned was in "The Recombination Hypothesis" (S5E13), a span of 115 episodes and her previous appearance was in "The Good Guy Fluctuation" which was 121 episodes ago.
- Sheldon and Amy also considered having baby using in-vitro fertilization and a surrogate mother in "The Robotic Manipulation", Amy's first full episode.
- Sheldon mentions the monkey that Amy had let stay in her apartment when she was teaching him to smoke. Amy was less worried about getting cancer from second hand smoke rather than having his face ripped off during the night.
- Amy is turned on by Sheldon's seduction antics.
- Sheldon is interested in having coitus to procreate and Amy turns him down since she doesn't want to get pregnant yet.
- In this episode, Sheldon and Amy notably switch personalities, with Sheldon wanting to move ahead in the relationship while Amy wants to wait for the right time.
- Sheldon: (to Amy, seductively, and while holding a glass of brandy) Care for a brandy?
- Amy: I don't think so.
- Sheldon: Good choice, it's disgusting.
- Leonard: Why does he need a baby? He's already hairless and smells like talcum powder.
- Penny: Could you two really have a super-intelligent child?
- Amy: Well there is a genetic component, but that doesn't guarantee anything.
- Leonard: That's true. Sheldon's father once picked a fight with a cactus.
- Penny: Yeah, but that's just his Earth parents. We don't know anything about the ones that sent him here.
- Leonard: Well, we know they were smart enough to send him away.
- Sheldon: [impressed] I have to say, it is nice to share this with someone who's on the same journey. Although, right now ours is testing off the charts while yours is floating around in it's own waste.
- Bernadette: [cross] Are you actually comparing my human baby to your brain in a bowl.
- Sheldon: Well, I didn't make you waddle up four flights of stairs for the heck of it.
- Bernadette: You do realize my baby has functioning organs and can recognizes voices.
- Sheldon: Yeah, but ours can recognize a specific data stream among background noises.
- Bernadette: Mine has a fully developed immune system.
- Sheldon: Ours doesn't need an immune system because it lives in a state-of-the-art German incubator.
- Amy: Sheldon, that's enough.
- Sheldon: Alright, you know what? Fine. Let's just agree that both creations are special in their own way, and it's foolish to compare them. [in a half-whisper to Amy] Although, we didn't need to have sex with Howard for ours, so we win.
- Raj: Hold on. Is that a wobble? Yes. There’s definitely a gravitational wobble.
- Isabella: Uh, sorry. I can could come back.
- Raj:: Oh, no. It’s okay. I-I just found a wobble.
- Isabella: Oh, do I need a mop?
- Raj: It’s a gravitational wobble. It could be a sign of an extra-solar planet that may contain life and someday be named after me.
- Isabella: Oh, well, if there is life maybe it already has a name?
- Sheldon: And you realize what the next step is?
- Amy: Set up a second culture and try to replicate our results.
- Sheldon: Uh, no. We lock that door, lower our underpants a little and make a baby.
- Amy: Make a baby? What are you talking about?
- Sheldon: Clearly the combination of our DNA is exceptional. Eh…Our child could be the next step in the evolution of mankind. We-we we’ll be able to get into any preschool we want.
- Amy: Sh-sheldon, I’m next ready to have a baby.
- Sheldon: Oh yes, yes you are. I track your cycle. For the next 36 hours you’re a fertile as a manure covered wheat field.
- Amy: Wow, I can actually feel the egg crawling its way back up.
- Sheldon: I don’t understand. I thought you’d be thrilled to procreate wilt me?
- Amy: Not right now.
- Sheldon: I see what’s happening here. You’re playing hard to get.
- Amy: I’m not playing anything. We’re not making a baby today.
- Sheldon: Very well. [Drops pencil.] Oops, how clumsy of me. You know what? Let me get that. Hey. Where are you going? I.. Did you even look at my bottom?
- Amy: [Sees trail of rose petals] Aw, man!
- Penny: Oh, Sheldon’s gonna get some.
- Leonard: Well, have fun with whatever nightmare’s behind door number two.
- Sheldon: [Walks in on Sheldon.] Well, hello.
- Amy: Hello.
- Sheldon: Would you care for a brandy?
- Amy: I don’t think so.
- Sheldon: Good choice. It’s disgusting.
- Amy: Sheldon, please stop trying to seduce me.
- Sheldon: Who’s trying to seduce you? After a long day I always turn on some smooth jazz and spray deer musk on my inner thighs.
- Amy: I thought is smelled like a petting zoo in here.
- Sheldon: Anything you’d like to pet? Not my hair. There’s a lot of goop in it.
- Amy: Okay, I’ve had enough. [Leaves.]
- Sheldon: Amy come back! I don’t know how to open the oysters.
- Penny: So were you turned on even a little bit?
- Amy: It was like being hit on by Rat Pack Pee-wee Herman.
- Leonard: I’m sorry, is that a yes?
- Amy: No!
- Sheldon: [Sheldon enters.] Amy. I didn’t want it to come to this, but you left me no choice but to employ the most seductive dance known to man. The flamenco.
- Amy: For God’s sake, you’re ridiculous. [Leaves.]
- Sheldon: You guys are aroused, right?
- (Penny and Leonard are confused and speechless)
- Amy: [Breathing heavily.] That was a close one.