Karmi enlists Hiro to help with a project with Sycorax: treating a person overrun with genetically engineered parasites. Meanwhile, Big Hero 6 has to deal with the entirety of Liv's monsters attacking the city.
Tropes in this episode include:
- Accidental Hug: When Hiro and Karmi’s experiment becomes a success, she hugs him in excitement. Then she awkwardly let him go, while Hiro is left with a Stunned Silence for the whole moment.
- Bait-and-Switch: Double subverted. Hiro's friends have noticed his Distressed Dude status and have taken to tailing him to ward off any future attempts. At the same time, Liv is in need of a robotics expert and decides to kidnap one. It's subverted when she targets Wendy Wower for her groundbreaking AI research and Big Hero 6 has to provide a rescue. It's then doubly subverted when Momokase informs Liv of Hiro's secret identity while Karmi informs her of their joint breakthrough in nanotechnology, so Liv has him kidnapped both for the nanobots and because it will cripple Big Hero 6.
- Book Ends: Both Liv at the beginning and Hiro at the end tell Karmi the same phrase: "We make a good team." Liv says it dismissively; Hiro is actually genuine.
- Broken Pedestal: Karmi finds out too late that Hiro was right about Liv.
- Cliffhanger: Karmi is turned into a monster, then kidnaps Hiro and steals the nanobots they invented. Meanwhile, Bessie has disabled Baymax, leaving him at the mercy of Chris and Liv.
- Defrosting Ice Queen: Karmi gets along surprising well with Hiro during the course of the episode, working with him on the nanobots to get them to work in conjunction with her organic solution.
- Distressed Dude: Hiro has been kidnapped so many times that his friends are now following him around as a precaution. Even Baymax points out Hiro has a problem with this.
- Empathy Doll Shot: As Karmi is mutating, the scene cuts away to her chicken pox virus plushie.
- Et Tu, Brute?: Hiro says this to Baymax when Baymax agrees with the others that he could use protection as a civilian.
- Face Plant: After a very meaningful (and awkward) conversation with Karmi, Hiro gets a call from Go Go and turns to leave...only for him to hit the door to her lab with his face.
- Gone Horribly Wrong: The real Liv engineered parasites that were meant to target and destroy viruses in the human body. As soon as she used them on herself, however, they mutated and began targeting healthy cells.
- Happy Dance: Fred does one when he hears about upgrades.Fred: New! Toy! Dance!
- Internal Reveal: Momakase reveals to Liv that Hiro is the leader of Big Hero 6.
- Irony: Liv overlooked Hiro as a possible intern in favor of Karmi because she believed they only needed Karmi's biochemstry expertise. As Karmi discovers, they also need a robotics expert, specifically one who can create nanobots.
- Jet Pack: Hiro designs one for Baymax. The boost in speed is secondary to the fact that it serves as an enormous battery to fuel Baymax's Overdrive mode, letting him go a few minutes before the power drain becomes an issue.
- No Name Given: The name of the doctor that helped Tadashi with making Baymax's medical chip is never given during the course of the episode. Only by watching the credits do you get her name: Lily.
- No-Sell: Wower sings annoyingly to get Sparkle to let her go. He actually likes it...but that doesn't stop him from kidnapping her.
- Not Helping Your Case: When Hiro tells his friends he's not a little kid, Aunt Cass comes in and offers Hiro milk and cookies, then she wipes some milk off his face.
- Oh, Crap!:
- Hiro appropriately freaks out when he hears Karmi beep and then sees Liv has attached one of her bio-transformation chips to Karmi's neck.
- Karmi when she finds out Liv's true motives for her.
- Omnidisciplinary Scientist: Subverted twice.
- Karmi attempts to branch into robotics when attempting to solve the problem of the parasites, but it's a complicated field and she can't just pick it up overnight. Hiro has to provide the robotics expertise, while her experience with biochemistry allows her to create workarounds for the interaction between technology and organic material.
- Hiro briefly grouses about how Karmi isn't like his brother, who would have needed both medical and robotics expertise to create Baymax. Baymax reveals that Tadashi did not in fact develop his medical chip alone, but had the help of an unnamed doctor.
- Painful Transformation: Unlike the villains who willingly let themselves get modified and don't exhibit any pain, Karmi's transformation at the end looks like it hurts a lot.
- Paper-Thin Disguise: The team follows Hiro around wearing helmets and fake mustaches underneath. Even the girls.
- Professor Guinea Pig: The real Liv tested her anti-virus parasites on herself.
- Pun: Mr. Sparkles claims he isn't a plant, he is a "fun-gi".
- The Reveal: The real Liv is being kept in stasis because she's infected with parasites that are killing her from the inside-out. Her copy is attempting to develop a cure.
- To Be Continued: Shown over a freeze frame of the final shot of Mutant Karmi carrying off Hiro.
- The Un-Smile: Liv gives Karmi one after Karmi shows she is learning basic robotics to help with making the cure.
- Villain Ball: "Liv" sending Mr Sparkles and the Mayoi to kidnap Wendy Wower is completely unnecessary, because Karmi, despite "Liv" having just deemed her no longer useful, does in fact come up with a cure by working with Hiro to combine their robotics and biochemical knowledge.
- Wham Shot: At the end of the episode, Hiro looks from the ground in shock as Karmi turns around at him, her transformation into a horrific monster complete.
- You Have Outlived Your Usefulness: Once Karmi informs Liv that she's developed nanobots with Hiro's help, Liv uses her as bait to capture Hiro and mutates her into a monster, as Karmi's biochemstry expertise is no longer required.
