"Nemesis" is the fifteenth episode in the sixth season of Adventure Time. It is the one hundred and seventy-first episode overall.
The episode begins with Kenneth entering an old comfort room. He meets a peanut man sitting on the toilet. The peanut asks him for his errand and then after answering, the peanut man presses a green button, opening a secret entrance from the urinal. The hidden passage leads to the hideout of Veritas Brigade where the members are having a meeting.
It is then shown from Princess Bubblegum's viewpoint that she is monitoring the Veritas Brigade through a hidden camera.
Back in the meeting, Kenneth rises from his seat to explain his invention, a device that broadcasts waves that can disrupt parallel dimensions. Starchie gets impressed and writes down information on his notepad. Suddenly, we hear laughing coming from the corner of the room. Peace Master is seen laughing and stands up from the dark corner and walks towards them telling how dangerous that device is. He walks up to Kenneth and slaps the device out of his hand which falls on Starchie's head. Peace Master explains how he hates evil. He warns everyone that there is a dark entity in Ooo (alerting Princess Bubblegum from her monitor.) He then finds out the camera which Princess Bubblegum used to spy on the meeting and tells that he is going to vanquish whoever was watching through that camera.
Back in Princess Bubblegum's viewpoint, the camera turns to static and triggers an alarm that sirens the whole Candy Kingdom.
Back in the meeting, Peace Master jumps out of the window. Starchie says that he'll be ready when Peace Master returns and takes a bite out of a pickle attached to the device.
Peace Master is now running to his mini-van where his three children are waiting. As he is driving, his daughter asks if she could go to a dark arts fair the next day to which he replies no. Then his son throws a boot at him which stresses him out. Suddenly his youngest child throws up on him causing him to crash the mini-van. He gets out and blames the accident on dark arts. He then kicks the vehicle repeatedly as Peppermint Butler watches him.
Back into the Candy Kingdom, Princess Bubblegum rushes into a door where some of the Candy Kingdom Military force are situated. She tells them to be alert as there is a threat in the Candy Kingdom but they do not listen.
Now we see Peppermint Butler go through a door and exit through another door in that room. After that, Princess Bubblegum opens the door and sits down and phones Finn and Jake.
In their house, their telephone is in the bathroom and is seen ringing. It then stops ringing and Finn and Jake rise up from a bathtub filled with water. Finn asks Jake how long his count was. Jake replies that his was three minutes, while Finn says that his own count was three minutes and 30 seconds. Rattleballs emerges from the bathtub as well, saying that his was 57 seconds. The three of them decide to continue and do it again.
Back to Princess Bubblegum, she puts the phone down and rushes towards the door Peppermint Butler is situated in. She asks for tea and we see Peppermint Butler doing some sort of meditation. She asks to leave the tea out for her and walks away.
Back to Peppermint Butler, he chants the Mangala Charan Mantra which transports him into another dimension. In that dimension, we see Peppermint Butler in another form and then armor appearing on him. He then charges towards Peace Master who is holding his baby. He tries to strike Peace Master with his Fire sword but Peace Master counters it back and kicks Peppermint Butler causing him to fall on the ground.
Back in the real world, Peace Master stands with the members of the meeting. He explains that he has found an evil one. After Peppermint Butler tries to attack Peace Master with a knife, he puts Peppermint Butler into his hat where it was going to slowly devour Peppermint Butler's candy flesh. Kenneth looks at the scene from a corner and disrupts the dimension Peppermint Butler was going to be transported to with his device. The hat falls to the ground releasing Peppermint Butler who drops a black smoke grenade before Peace Master could get him. In the smoke, Peace Master challenged Peppermint Butler to a battle at Wizard Battle Arena with his charm sack which Peppermint Butler accepts.
Now at Wizard Battle Arena, we see Peace Master walking up to the field when suddenly a huge creature arises from the grass with a big cylinder bag that opens up and shows Peppermint Butler walking out. Peppermint Butler walks up to Peace Master with a cape and opens it to show Peace Master's children. He turns one of them into a flying monster. Peppermint Butler warns Peace Master that if he does not give up his charm sack, he will turn another one of his children into a monster. Peace Master refused and so Peppermint Butler changed his daughter into a flying fairy. Peace Master finally gives up and tosses his charm sack into a hole. After that Peace Master is forced to show them his underwear, walk like a chicken and eat dirt before he could leave with his children, until Peppermint Butler realized that he himself had gone too far.
At a corner, Peppermint Butler watches Peace Master leave and then walks away. We then see a CCTV camera through which Colonel Candy Corn is spying on a snail licking a plant. He then reports it to Princess Bubblegum at the side, but she is looking for Peace Master. The episode ends after Peppermint Butler gives Princess Bubblegum tea and walks out.
- Banana Guard
- Colonel Candy Corn
- Nurse Pound Cake
- Gumball Guardian
- The Peace Master and his children seem to be the same species as Ron James, as they have the same skin color, head shape, and neck size as him.
- More modern vehicles have been invented in Ooo as the Peace Master drives a minivan.
- Although it can be presumed as just an approximation of past technologies, the minivan's design still seems to be derived from a combination of various generations of the Toyota Sienna. (the rear most resembles that of a fourth-generation model.)
- The license plate on Peace Master's car spells "MIR" which means "peace" in Slavic languages.
- This episode features a secret society called the Veritas Brigade headed by Starchie. Veritas is Latin for truth; they also have a Latin motto "Lux in tenebris" which translates to "Light in the darkness."
- The society's pass-phrase is a reference to "The Romance of Britomarte," a poem written by Adam Lindsay Gordon.
- During his ritual assault on the Peace Master, Peppermint Butler uses one of the world's oldest prayers, a protective Sanskrit mantra from the Guru Granth Sahib, the central text of Sikhism.
- The Mangala Charan Mantra goes "Aad Guray Nameh, Jugaad Guray Nameh, Sat Guray Nameh, Siri Guru Devay Nameh," which translates to "I bow to the primal wisdom, I bow to the wisdom through the ages, I bow to the true wisdom, I bow to the great unseen wisdom," and is supposed to clear the clouds of doubt and open one up to guidance and protection.
- While Peppermint Butler uses chants from Sikhism during the ritual, the mention of Horus and the crocodiles (Crocodiles of the Nile are often mentioned in Hermetic texts) seem to reference Hermeticism. (Peppermint Butler has been linked to the Hermetic Order of the Golden Dawn before.)
- During the ritual Peppermint Butler also refers to the light of the hermit. This is likely a reference to the ninth tarot card of the major arcana: The Hermit. There are many interpretations of this card but Aleistar Crowley's Book of Thoth may be the most relevant, considering Peppermint Butlers connections to Crowley. The Book of Thoth talks specifically about light of the hermit.
- During Peppermint Buttler's ritual to transform and transport himself to where the Peace Master is, everything turns to black and white and is visually similar in animation to A-ha's music video, "Take On Me."
- Colonel Candy Corn is seen training the Banana Guards through a miniature figure role-playing game, notable through various games such as the Warhammer franchise.
- Peace Master singing "Da na-na-na na-na…Peace Master!" is most likely a reference to the well-known theme of the 1960s Batman series.
- Rattleballs is seen training Finn and Jake; Finn started his training in the episode "Rattleballs."
- The stadium where the Peace Master and Peppermint Butler reunited was the same stadium from "Wizard Battle."
- This is the third episode where Peppermint Butler is seen using dark magic, the first two being "Death in Bloom" and "The Suitor."
- Additionally, he opens a path through the corner of a room just as he did to open a portal in "Death in Bloom".
- Starchie continues to collect conspiracies within the Candy Kingdom, being first noted in doing this through his radio show in "We Fixed a Truck."
- Princess Bubblegum still displays a Big Brother leadership role as she keeps surveillance on her subjects like in "Apple Wedding."
- After Princess Bubblegum calls the red alert and the scene switches back to the secret hideout, the title card music from "All Your Fault" plays.