Fred is in the room reading comics with Mini-Max until his Mom calls for him. They are expecting a guest for dinner, Orso Knox, and Fred needs to be properly dressed for the occasion. He tells her he is dressed for dinner and then goes back to reading his comic. Suddenly, a monster bursts into his room. Mini-Max jumps in to fight it off, but the monster throws him to one said. It then for the portrait of Fred's father, and then corners Fred. The monster gives off a loud roar, says a few words and then runs off just before Mrs. Frederickson shows up to find her son's room vandalised.
Hiro, Baymax, and Go Go later arrive at the scene. Fred tells the about the monster, who describes it to be a combination of a whale and a dinosaur with hair. Mini-Max, who suffered some damage, provides everyone with a visual image of the monster. Baymax identifies the slobber it left behind to be from an unknown species, deducing it to be an actual monster. Fred suspects that it is another old foe of his dad's out for revenge. The next day at the SFIT labs, Fred, Hiro, and Honey Lemon rummage through large amount of files on all the enemies Fred's dad had as a superhero. So far they have found no match. Just then, Wasabi and Go Go show up to tell everyone that Granville was coming, not looking much like her usual self. When Granville does show up, she looks very excited. Self-made billionaire and founder of Sycorax, Liv Amara is visiting the school. She is funding SFIT's new bio-tech center, which will be named in her honor during a donation ceremony later in the week. She has also heard abotu Baymax and would to meet him and his supposed creator, Hiro. Amara's helicopter arrives, and Granville goes off to get her. Karmi suddenly rushes in all excited. She is a huge admirer of Liv Amara and hopes to meet. Granville soon arrives back with Amara. She introduces her to Hiro and Baymax. Amara is at first impressed with the robot, but quickly loses interest after learning that Hiro did not actually create him. On the way out, she meets Karmi, who shows off her latest invention to her: extradermal nano-receptors. Amara is so impressed that she invites Karmi to see the new bio-tech building with her. As for Hiro, he is left feeling envious because Karmi was succeeded in wowing Amara.
Meanwhile at Krei Tech Industries, Krei is in his office when suddenly the monster that attacked Fred bursts in. Like before, the beast says a few words, and leaves after terrorizing Krei. Honey Lenon, Go Go, and Fred later arrive at the scene. Krei gives them the same description Fred gave and re-quotes what the monster said "This thing of darkness I acknowledge mine". Much of a coincidence, Krei was supposed to be meeting with an investor, Orso Knox. The same man who was supposed to visit Fred's mother on the night the monster attacked his house.
Back at SFIT, Baymax finds Hiro building a temperature gradient device, which converts physical changes in heat to an understandable numerical value. He hopes to impress Liv Amara with this invention. Hiro finds her in the dining hall having lunch with Karmi, getting well acquainted. He shows off his invention to her, but she is not wowed by it since all he built was a big thermometer. Later that evening, Hiro, Baymax, Honey, and Fred visit Orso Knox's house to see if there is some connection between him and the monster. Mr. Knox is not at home, but they find the house opened and ransacked. As they search the office, the monster bursts in and attacks. Honey and Fred put up a fight, but the monster turns out to be tougher to beat. Hiro notices the monster is going for Mr. Knox's schedule. He tries to get to it first, but the monster grabs him and says "All the devils are here". On Hiro's command, Baymax switches to overdrive mode and frightens away the monster. However like before, overdrive mode drains his power, and he collapses after changing back. The four friends return to Frederickson Manor, pondering over the clues they have. Honey finds out that all the things the monster said are quotes from Shakespeare's play, The Tempest. They all know that Knox was a Shakespeare's fan, and by putting two and two together they deduce that the monster is actually Knox himself. Looking back at his schedule, they also figure out the attacks on Fred's house and Krei's office both occurred at the time of his appointments. This helps them deduce that Knox will attack Liv Amara next during the gala at SFIT.
On the day of the donation gala, Hiro upgrades everyone's supersuits with ultra armor. His friends notice that he is still jealous of Karmi's success with Amara, since he has started scoring his and her accomplishments. They each bring him down to earth, saying he cannot out best everyone. Karmi is special in ways that Hiro is not, which goes the same for himself and everyone else.
At the donation gala, Baymax, Wasabi, and Fred are on the look out for the monster while Hiro, Honey, and Go Go attend the ceremony. The gala is being held inside a large tent, filled with many rich and powerful people, including Krei. As the party goes on, the Orso Knox monster shows up just as Liv Amara takes to the stage to give a speech. Baymax, Wasabi, and Fred hold off the monster while Honey and Go Go, suited up, evacuate the guests from the tent. Big Hero 6 lure the monster into the tent and try to trap him inside, throwing everything they have. Despite all their efforts, the beast just breaks away from their restrains. The monster is about to attack Liv Amara, but Karmi uses her nano-receptors to sedate the monster. Not only does this save the day, but it also gives Liv further incentive to support Karmi and her endeavors. She also offers to take the monster in and have her team find a way to cure Mr. Knox of his monster mutation. As they prepare to transport him, Hiro thanks Karmi for her assistance despite his jealousy. Karmi responds by awkwardly professing her love for the hero, which embarrasses Hiro.
- Ryan Potter as Hiro Hamada
- Scott Adsit as Baymax
- Génesis Rodríguez as Honey Lemon, Red Headed Guest
- Khary Payton as Wasabi
- Jamie Chung as Go Go Tomago
- Brooks Wheelan as Fred
- John Michael Higgins as Mini-Max, Ticket Taker
- Haley Tju as Karmi
- Jenifer Lewis as Professor Granville
- Mara Wilson as Liv Amara
- Laura Silverman as Judy
- Susan Sullivan as Mrs. Frederickson
- Fred Tatasciore as Orso Knox/Monster, Soul Patch Guy
- Alan Tudyk as Alistair Krei
- Professor Granville's first name is revealed to be Grace as referred to by Liv.
- The scene in which Liv meets Baymax is reminiscent of the scene where Hiro first meets Baymax in the original movie.
- The photos that Krei admires early in the episode are based on shots from the original movie.
- Orso Knox is a fan of the Shakespeare play The Tempest. Ironically, Liv Amara's company is called "Sycorax" who was the mentioned witch and mother of Caliban from The Tempest.
- Knox's monster roars are those of a lion or tiger and the roars of the Tyrannosaurus Rex from the Jurassic Park films.
- During the Gala, Hiro, Honey Lemon, and Go Go are dressed in their waiter outfits from "Fred's Bro-Tillion".
- The team's ultra-armor costumes are based on the "Stealth Mode" action figure variants Bandai produced in 2015.