Calvin is struggling to repair the MTM after it was overloaded in the previous episode, and Hobbes and Socrates are planning a new prank on him. Since the MTM's holographic technology is damaged beyond repair, Calvin instead decides to install a voice chip for easier communication. After a moment, the MTM starts to talk. He has a British accent, and a very sarcastic attitude, much to the group's annoyance.

Meanwhile, Dr Brainstorm is targeting the MTM as well, recognizing it as Calvin's most powerful invention. He and Jack make plans to steal it.

MTM's talkative nature and on-the-dot pin-point accuracy begins to grate on the gang's nerves. They can't play Calvinball without being corrected, and they all try to pawn him off on each other. Finally, Calvin just switches him off before bed time.

At that time, however, he and Hobbes are captured by Dr Brainstorm and Jack, and they are taken back to the lab in Yellowstone. He locks up the pair in a cell, and then he takes the MTM to find out which button will help him take over the world. In the process, he switches the MTM back on, and it begins to talk to him, and eventually he flat out annoys him as well by not doing what he says. Dr Brainstorm proceeds to push random buttons, getting himself blasted by a laser. MTM reveals he responds only to Calvin's voice, and in a fit of frustration, Dr Brainstorm slams his fist down on the CD player, hitting several buttons at once. This apparently activates an Attack Option, which involves Dr B getting himself blown up.

With that done, Jack lets Calvin and Hobbes go and returns the MTM, where it is revealed that there is no Attack Option, and he just wanted to blow up the mad scientist, proving his loyalty to Calvin overrides his circuitry.

The next day, Hobbes convinces Calvin that Socrates is in the Calvinball Field and is in trouble. Once he gets there, he steps on some string, causing a dart to go flying past his face. While an elaborate mouse trap is going off, he has MTM scan the area, and the CD player tells him to step to the right. Socrates suddenly appears, and he runs at Calvin to put him back, but by then, the trap has completed, and a trap door opens up where Calvin was standing, and Socrates falls in instead. Pleased that MTM's Prank Sensory Chip is working, Calvin takes the MTM home for tea.

!!Tropes:
* BagOfKidnapping: How Brainstorm manages to capture Calvin and Hobbes.
* BritishAccents: The MTM has one.
* TheLoad: The MTM quickly becomes this. He even drives ''Brainstorm'' into SanitySlippage!
--> '''Jack''': He was saying something of the lines of "It just wouldn't shut up".
* TotallyRadical: The MTM's first words: "Alright, dudes? How's it hanging?"
* SanitySlippage: The MTM drives most of our main cast and even Dr Brainstorm into this territory.
* StuffBlowingUp: The MTM warns Sherman about this happening to his current experiment. [[TemptingFate He doesn't listen.]]
** The MTM blows up Dr Brainstorm towards the end of the episode.
* YouCanTalk: Everyone's reaction to hearing the now modified MTM.
--> '''Brainstorm''': AAK! IT SPEAKS!