Shamy plot: Sheldon and Amy begin to collaborate on a scientific project when Sheldon realizes something she's been working on could have implications with regard to a challenging issue in quantum mechanics. They try to work out some ground rules between them for this new kind of interaction and find that being snarky with one another helps their cognitive thought processes.
Other plot: Raj and Penny get along so well doing various "girly" activities together that Leonard feels left out. He spends some time with Howard and Bernadette before bringing it up to Raj and Penny.
Thanks to the report from RJ1013.
- Guest starring:
- Teleplay: Steven Molaro, Steve Holland & Dave Goetsch
- Story: Chuck Lorre, Tara Hernandez & Giuseppe Graziano
- Title Reference: Refers to Sheldon and Amy working together and how they "fluctuate" between working and insulting each other.
- Taping date: March 7, 2017
- This episode was watched by 12.78 million people with a rating of 2.6 (adults 18-49).
- Total viewers including DVR users 17.18 million.
- The Big Bang Theory was ranked #x for the week ending xx April 2017.
- This episode aired in Canada on March 30, 2017.
- Chuck Lorre's vanity card 
- Caroline Preece at Den of Geek! - Very little is most likely just enough for the majority of the show’s viewers, but there are others who’ll always demand more. That’s been the problem with Leonard and Penny this season - the writers have cycled through everything they had planned for the male and female lead, and there’s nothing left. They’re left with scraps while the better writing goes towards Sheldon and sometimes Howard. Which is why having Raj move into the main apartment was a great idea. It’s not going to set anybody’s world on fire, but it’s a fun change of dynamic that solves two of The Big Bang Theory’s major issues. It gives them an excuse to write a A-plot involving Penny and Leonard, and it puts Raj front and center.  IMDb user reviews
- Raj and Penny start to bond over common interests.
- Sheldon and Amy begin working on a science project together.
- This episode was the closest to a moment where Leonard or Bernadette would be having a conversation in a nice sweet and, to some degree, helpful way with the other. The last episode where someone spoke nicely to the other was in the final scene of "The Deception Verification" (S7E2) where Bernadette tells Leonard in a sweet voice and smiling that Raj was able to talk in front of the girls without a beer right after Leonard left for his expedition to the North Sea.
- Raj: So, Downward Facing Dog comes from the Sanskrit phrase Adho Mukha Svanasana.
- Penny: Oh, that's beautiful. What does it mean?
- Raj: Downward facing dog.
- Penny: Yeah, I guess they don't have Sanskrit for butts up and heads down.
- Raj: Hey, we wrote the Kama Sutra; if it involves butts there's a word for it.
- Sheldon: Can you read them back?
- Amy: Revised ground rule number one: we are on the same team but it *is* a competition.
- Sheldon: Excellent, excellent. And on a related point, you're going down, punk.
- Amy: Revised ground rule number two: there are definitely stupid questions, and those who ask them can be told so right to their *stupid* face.
- Sheldon: I love that one.
- Amy: Thanks, babe. Number three: fair topics for insult include educational pedigree, scientific field, intellectual prowess, and mommas.
- Sheldon: That list is *strong*. Like your mother's urge to be promiscuous with sailors.
- Sheldon: I believe I've made some progress on our ground rules.
- Amy: Oh, good. What are they?
- Sheldon: Number one: in matters of physics, I have the final say. In matters of neuroscience, you have the final say, unless I disagree. Number two: when we publish, my name goes first. Oh, subsequently, if we win any awards, I speak first. I don't want to be talking when the orchestra plays us off.
- Amy: Can I see that?
- Sheldon: Of course. [Amy takes notebook and tosses it out the window]
- Sheldon: I'll get that back. Like all my underwear, that notebook says "Property of Sheldon Cooper".
- Amy: Sheldon, if we're gonna have ground rules, I'll tell you the first ground rule: I make the ground rules.
- Sheldon: I'd write that down, but I can't, now can it?
- Amy: We're finally making progress. I wish we could do it without fighting.
- Sheldon: What if the fighting is the reason we're making progress?
- Amy: I suppose it's conceivable that the hormones associated with our fight or flight response could be sharpening our cognitive processes.
- Amy: I had a feeling you were using the wrong computational model, but I didn't say anything 'cause you're so sensitive!
- Sheldon: Just because I'm easily bothered by light, heat, sound, smell and the way birds look at me does not mean I'm sensitive!
- Sheldon: Gentlemen, the most interesting thing just happened with this spoon.
- Howard: Unless it was singing "Be Our Guest", I doubt it.
- Amy: [Looking at their boards] Wow. Look at that.
- Sheldon: Yes. It's remarkable.
- Amy: So we're agreed: it's total garbage.
- Sheldon: By the way, your name can go first.
- Amy: [after carrying her harp up the stairs] You know, I like harp lessons, but I'm thinking of switching to elevator repair lessons.
- Sheldon: Can you stop breathing so loud? I can hear your nose whistling.
- Amy: I can hear your face talking, so we're even. [Beat]
- Sheldon: All right! Either blow your nose or teach it to play Camptown Races!
- Amy: FIne! Fine! You want me to blow my nose? Here, I'll blow it! [Blows nose really hard at Sheldon]
- Amy: Better?
- Sheldon: No, I can still hear it. Oh, wait, that's me. Never mind, it's fine.