The gang is gathered outside the cinema, waiting to see Kentucky Kaiju, despite the fact that Fred has already seen the movie more than six times. Just then, they receive a news report of Globby robbing a bank. Big Hero 6 suit up and arrive at the scene. Globby catches them off guard and attacks. He removes Hiro from Baymax and takes out all his friends. As he does so, Globby mocks Hiro about how helpless he is without his friends to protect him. He then escapes, and returns to Obake. Little did they know that Obake sent Globby to plant doubt into Hiro. Now he waits to see what he will do next, wrapped with doubt.
As Obake hoped for, Hiro was feeling doubtful and fed up with being weak and useless, and having to depend on others. His friends had superpowers and he did not. So, he decides to give himself super strength by designing a nano suit that can contract to enhance natural muscle movement. Meanwhile, Fred is at the harbor waiting for a large shipment to be unloaded. He had just bought the actual Kentucky Kaiju animatronic from the movie. However, he was expecting it to be big and was disappointed to realise it was small enough to be a toy. But then he has an idea when he looks up and notices the cranes in the harbor. Back at the Lucky Cat Café, Hiro has made his new nano suit, which he calls Nanodex. Just then, they here from Go Go that Noodle Burger Boy is back and on a rampage in a armored hovercraft. Honey, Go Go, Wasabi, and Fred are already engaging the robotic mascot, and later Hiro and Baymax arrive. Wearing his new nano suit, Hiro takes on Noodle Burger Boy singled handed. Each time he throws a car at him, Hiro throws it back. Noodle Burger Boy quickly becomes overpowered, especially when Hiro causes a lot of damage to his hovercraft. Noodle Burger Boy is forced to limp away.
Following his victory, Hiro starts wearing the nano suit more daily under his clothing. Having enhanced strength proves useful, but during school he starts to have trouble controlling it. He ends up accidentally ripping doors off their hinges and knocking chairs across the classroom. Hiro tries to be gentle, but no matter how hard he tries he ends up breaking things and making a mess. He tries to take off the nano suit, only to discover that its stuck to him. The more he tries to pull it off the tighter it gets. The problem is Hiro rushed through making the suit. After failing to remove the suit by using Baymax's defibrillator hands to short out the circuitry, Hiro and Baymax go to Fred's to see if he has a comic solution. Little did they know that Obake was among the customers at the Lucky Cat Café, watching them.
Unfortunately, Fred does not have anything that could help Hiro, and quickly runs off after getting an expected phone call. Shortly after he leaves the room, his father, Mr. Frederickson appears on the big screen. He is currently in Egypt exploring an ancient pyramid full of living mummies. He was expecting to see his son, but instead meets Hiro. Noticing his nano suit, Mr. Frederickson recalls the time when he tried to give himself super strength and realised he didn't have to be strong to be a superhero. He just had to find his true strength, which in Mr. Frederickson's case was his can do attitude and his fortune. This makes Hiro wander what his true strength is.
Later on, Fred has gathered his friends at the harbour to see his giant Kentucky Kaiju robot, made from a giant crane. Just then, Noodle Burger Boy shows up. He seizes control of the Kaiju, and takes it on a monster rampage through the city. Big Hero 6 arrive at the scene and engage the monster. The fight against the Kaiju proves tough to beat. Fred, Honey Lemon, Wasabi and Go Go are quickly incapacitated. After Baymax suffers damage that makes him unable to move, Hiro is the only one still standing. He climbs onto the Kaiju and makes it to the controls, only to discover that Noodle Burger Boy has left the monster operating on its own. Hiro rushes over to the controls, but is shaken out of the monster. In his struggle to fight off the Kaiju, his nano suit disables on him at a crucial time, leaving him powerless. However, remembering what Mr. Frederickson said finding his true strength, Hiro uses his wits to trick the monster into stepping into some high-voltage electric wire, short circuiting itself.
The Kaiju is defeated and Hiro has saved the day by only relying on his true strength, his smarts. Rummaging through the rubble, Hiro finds an incredibly advance CPU that was installed into the monster by Noodle Burger Boy. He also recalls that when Globby broke into the bank he did not steal anything. He was actually to trying to get into Hiro's head, which he did. All this makes Hiro suspect that someone else is responsible for all that has been going on lately. He does not know who, but intends to find out. Meanwhile from afar, Obake has been observing the whole thing, and is satisfied knowing how smart Hiro is: very.
- Ryan Potter as Hiro Hamada
- Scott Adsit as Baymax
- Génesis Rodríguez as Honey Lemon
- Khary Payton as Wasabi
- Jamie Chung as Go Go Tomago
- Brooks Wheelan as Fred
- Andrew Scott as Obake
- Maya Rudolph as Aunt Cass
- Stan Lee as Mr. Frederickson
- Lucas Neff as Noodle Burger Boy
- Andy Richter as Globby
- Jenifer Lewis as Professor Granville
- Haley Tju as Karmi
- David Shaughnessy as Heathcliff, Moviegoer
- The line Obake quotes "Our doubts are traitors, and make us lose the good we oft might win, by fearing to attempt" is from William Shakespeare's play Measure for Measure.
- This is the first episode in which the Big Hero 6 battle two different villains, albeit previously encountered foes, in one episode.
- Fred creating and piloting a giant kaiju creature is almost similar to his comic book counterpart in which he surrounded himself with a giant kaiju aura.
- The scene where Hiro builds his nano suit references the scene where he built Baymax's first armor in the film.