The main episode opens up with Frylock boring his roommates with his lecture on improving computer technology faced with microscopic limitation. When Frylock ultimately reveals his shrink ray, Shake and Meatwad go crazy with it until Frylock apprehends the ray from Master Shake. When Frylock tries to open up his roommates to the possibilities of the shrink ray, Shake and Meatwad can only think of personal gain, such as a pool or a overgrown hot dog. When Frylock shrinks a computer chip, Meatwad mistakes it for a potato chip and eats it. Frylock, in an attempt to get his computer chip back, makes Meatwad drink a mixture of mustard, vinegar and oyster sauce to clean out Meatwad's systems. Meatwad however voluntarily enjoys the drink at the mention of it having oyster sauce. He request another.Jealous of the attention Meatwad has received, Shake drinks the second drink which Frylock may have urinated in, which causes him to vomit intensely. Shake goes to lie down while Meatwad enjoys snacking on Shake's vomit. Frylock reveals his intentions with Meatwad, but Meatwad reveals that he cannot excrete matter, comparing his body to the Thunderdome. Meatwad gets Frylock to say "poop" and laughs about it, while Shake is still vomiting from the drink. Frylock's plan, which is modified from Meatwad's plan, is to shrink himself and have Shake inject Frylock into Meatwad's body. Shake, however, starts to shrink Meatwad instead. After Shake shrinks Frylock, Shake leaves the house and enlarges Carl's pool.
A shrunken Carl is thrown into a setting with a miniature Frylock. Shake, playing with Carl's insecurities, has Carl fighting Frylock. Meanwhile, Shake is messing with the shrink ray on Carl and Frylock. Frylock gets Carl to cooperate under the condition that Frylock will help Carl with enlarging Carl's manhood. Shake makes a "hail storm" of orange soda on his two friends, which Frylock reacts with his own rays. After this fails, Shake decides to "compare rays" and shrinks Frylock to a very microscopic size. Shake then throws Meatwad into the battlefield with Carl. The latter forfeiting out of frustration.
A sleeping Master Shake, next to an enlarged hotdog wiener, is woken up by Carl, Meatwad, and Frylock who are now small enough that they have crawled into Shake's brain, which Shake denies having, prompting the others to acknowledge this. Frylock then reveals he's short circuited Shake's nerves to take control of him, and proceeds to have Shake beat himself with a baseball bat and cut off his tongue with a chainsaw as punishment for his hijinks. Frylock gets Shake to increase Meatwad with the shrink ray two times his size, but Meatwad does not return the favor, instead finding amusement in the overgrown hot dog.
While fallen asleep, Meatwad is waken up by Frylock but Frylock is not inside of Meatwad. And Carl is not inside of Meatwad, too. After Meatwad is waken up by Frylock, Meatwad offers Frylock some of the overgrown hot dog. In Frylock's room, Carl is getting ready to increase his "package." Frylock reveals to Meatwad that Carl and Frylock had to blow out one of Shake's eyeballs to get out. After Carl "enhances" himself, the previous items that had been shrunk or enlarged go back to normal size, including the giant chip which expands Meatwad to its shape. Carl offers to buy the shrink ray after Frylock opts to destroy it, only for Frylock to immediately do just that. All of a sudden, giant crab lice start to pop out of Carl's pants, to which he suggests Frylock "hit them with the shampoo."
- Master Shake is presumably dead after being tortured.
- The title and premise of this episode is a parody of the movie "Fantastic Voyage", in which a team is shrunk and injected into a person's body.
- Meatwad makes a reference to the film Mad Max Beyond Thunderdome.
- Carl uses Frylock's shrink ray to enlarge his penis at the end, but earlier in the episode, the shrink ray made the characters' as a whole larger or smaller, not just a specific aimed area.
- In Interfection, Shake says he doesn't have teeth, but in this episode he says "My teeth feel gritty."
- An integrated circuit or monolithic integrated circuit (also referred to as IC, chip, or microchip) is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material. Additional materials are deposited and patterned to form interconnections between semiconductor devices.
- Shake is presumed dead at the end of the episode.