Amy breaking up with Sheldon leaves him far more shaken up than he expected. Leonard and Penny elope to Vegas, only to realize they have unresolved issues that they struggle to overcome.
Tropes in The Big Bang Theory Season Nine
- Almighty Janitor: In an episode where Leonard and Sheldon have to get a black market supply of helium for an experiment, the guy they had to deal with was surprisingly intelligent, having a debate with Sheldon on proper language choice to describe the scenario they were in. While maybe just faking it, he also seemed to understand the specifics of their experiment when it is described to him.
- Artistic License – Chemistry: When the guys get a flat tire in Mexico, they try to get the lug nut off by improvising thermite by mixing rust and aluminum shavings. The problem is, they're shown igniting the thermite with a wooden match, which wouldn't burn nearly hot enough to do the job. In fairness, the mixture is very rudimentary and we never actually see the thermite ignite, but we do see the results.
- Break the Haughty: What has slowly been happening to Sheldon after his break up with Amy.
- The Bus Came Back:
- Penny's father Wyatt returns in "The Bachelor Party Corrosion." He had not been seen since his first appearance in Season 4.
- Leslie Winkle returns in "The Celebration Experimentation." She had not been seen since Season 3.
- Penny's old boyfriend Zach reappears in "The Fermentation Bifurcation."
- Cant Get Away With Nothing: Played with in "The Solder Excursive Diversion," Penny and Bernadette visit Leonard and Howard at the office working on a project, and are able to help with a simple but time consuming task. Leonard and Howard leave to get more solder, but get drawn into a test screening for Suicide Squad (2016), so they lie to the girls that they got a flat tire. Raj happened to be hanging with the girls when he got a text from Howard mocking him about the screening, and they all end up plotting their revenge for the lie. To their surprise, Leonard and Howard return with flowers and confess to the lie immediately, offering them dinner in return, making their efforts to catch them in their lie useless.
- Celebrity Paradox: A surprising inversion happens. Sheldon ends up being interviewed for a Real Life documentary about the life and career of Leonard Nimoy being developed by his son Adam, who appears on the show. The actual documentary, For the Love of Spock, includes an interview with Jim Parsons on the set of The Big Bang Theory.
- Did You Think I Can't Feel?: Multiple times in "The Line Substitution Solution" when Beverly Hofstader visits. In the ride from the airport Beverly made a joke about psychoanalyzing Penny's desire not to get psychoanalyzed, which caught Penny by surprise because she didn't think Beverly made jokes. Penny later tries to call her out for treating her poorly, and Beverly admitted to being upset that she and Leonard got married without inviting her or telling her what they were doing. She says she always thought the two of them getting married was a bad idea, but also admits she is pleased that Leonard seems to be happy with her. It's actually the first time she's shown any concern or interest towards Leonard that wasn't spurned by his nagging.
- In "The Earworm Reverberation," Sheldon is pestered by this trope, which sounds like "low F♯ F♯ E E♭ E E." It's "Darlin'" by The Beach Boys.
- Epic Fail: The guys try to change the tire of Richard Feynman's van when taking a road trip for Leonard's bachelor party. They end up setting it on fire.
- Flynning: "The Perspiration Implementation" has the guys take a fencing class together with Kripke as teacher. While they spend time learning proper technique, whenever Kripke turns his back they end up spicing it up with clumsy flailing.
- Insecure Love Interest: Leonard and Penny are this during the season opening, after speaking with the girl he kissed, Leonard and Penny realise they sabotaged their relationship due to not feeling they are worthy of each other.
- I Never: Played by Penny, Leonard, Sheldon and Amy in "The Big Bear Precipitation". It leads to a serious argument between Leonard and Penny when Sheldon reveals through the game that Leonard keeps a separate bank account secret from Penny.
- It's a Costume Party, I Swear!: In "The Viewing Party Combustion," Stuart comes to the guys' Game of Thrones viewing party dressed in a Night Watch costume because Howard told him everyone else was going in costume as well.
- Ma'am Shock: Penny in "The Valentino Submergence" gets upset when the maître d' at the restaurant she and Leonard were trying to get a table calls her "ma'am."
- Make Up or Break Up : As of the Season 9 premiere, Leonard and Penny get married but the occasion is marred by a big fight and they spend the night apart. Likewise, Amy resolves the question of the Season 8 finale by dumping Sheldon for insulting her.
- Prayer Is a Last Resort: Played for Laughs. Sheldon starts praying when the website to buy Star Wars premiere tickets freezes... but when Howard says he got the tickets, Sheldon shouts that he will continue denying God's existence.
- "The Reason You Suck" Speech: Amy delivers one to Sheldon in the Season 9 premiere before they break up.
- Seinfeldian Conversation: In "The Helium Insufficiency" Leonard and Sheldon deal with a Black Market dealer to get a large source of helium to perform an experiment. The guy they dealt with, Kenny, ended up being surprisingly well read and he and Sheldon had an extensive debate on language protocol regarding if they were in a stand-off, stalemate or impasse.
- Waxing Lyrical: At their Vegas wedding, Penny found herself quoting "You Got A Friend In Me" from Toy Story. Silly, maybe, but being his favorite movie Leonard was in tears.
- Wham Line: Near the end of "The Valentino Submergence," Bernadette privately mentions that she is pregnant.
- Sheldon talks about what to give Amy for her birthday and concludes he is ready to have sex with her. Penny snaps a wineglass with one hand from that announcement.
- What the Hell, Hero?: Raj's decision to break up with Emily (right before Valentine's Day) to pursue a relationship with Claire (who initially wasn't even interested in him) didn't go down well with...well, anybody.Claire: Sorry, I just got back with my boyfriend.
Raj: But I just broke up with my girlfriend!
Claire: Right before Valentine's day? What an ass!
