The episode begins where Part 1 left off, with BMO charging Jake's phone. Jake is wearing a green towel and a blue shower cap (presumably having just had the shower referred to at the end of the previous episode). The phone has finally charged, and Finn and Jake proceed to watch videos of their time in the Nightosphere. There are three videos on the phone. The first one shows Finn and Jake fooling around with the camera before entering the Nightosphere to hang out with Marceline, at her offer to come with her. The second shows a scene in which Marceline's dad flies in abruptly to tell Marceline that he wishes for her to take over the family business and rule the Nightosphere. He casually takes off and gives her a purple amulet that he says can grant wishes. Marceline refuses to take over her dad's job, and plays a short song after he leaves - Marceline plays the banjo and sings, and Finn plays a tambourine. Though she claims that she has her own plans for life, she tries on the amulet and accidentally turns herself into an evil monster like her dad. The video blacks out as a third video comes on, showing how Finn and Jake got thrown in their jail cell by the Nightosphere Jailer, who spews bananas profusely from each of his ears in a way that suggests that bananas are the equivalent of feces or vomit to demons. Jake and Finn make grossed-out faces at each other, and Jake drops the banana he has been carrying.
They decide to return to the Nightosphere to save her. After disguising themselves as demons, with Finn using a cut-up paper plate and pajamas and Jake using his stretching powers to alter his appearance and take the form of a gross, sharp-toothed demon, they go back using the spell that Finn used to open a portal to the Nightosphere in "It Came from the Nightosphere." When they re-enter, they find themselves trapped in yet another line, but one which they believe leads to Hunson Abadeer, who is playing cruel tricks on the demons of the Nightosphere. They are discovered by the giant overruling demon when they try to cut in line, and barely escape after it attempts to eat them. They run into her house and find the Lord of Evil, the actual Hunson Abadeer, making a sandwich. He explains to them that he only wanted Marceline to follow in his footsteps and that he thinks it is great that she has been possessed by the amulet. Hearing this, Finn gets angry, slapping the Lord of Evil's sandwich out of his hands, and goes back to rescue Marceline.
Finn and Jake decide they need a way to get close to Marceline and start a political rap. Soon after hearing their song, other demons join them in the revolution to overthrow Marceline. They reach Marceline and finally manage to take off the amulet that was controlling her. However, Jake is unable to go back to the portal they created before as the demons try to eat his legs, disabling him. So Finn puts on the amulet and throws Jake and Marceline out of the Nightosphere. Unfortunately, under the control of the amulet, he tries to get Jake and Marceline back to the Nightosphere as he has become evil, but the Lord of Evil rips the amulet off Finn and puts it back on, explaining to Marceline that he is proud of her no matter what she does, and that he actually likes her friends (Finn and Jake). Marceline closes the Nightosphere portal, and after stating her surprise at her dad for liking Finn and Jake, she jokingly says she does not want to hang out with them anymore. The episode ends with Marceline asking Finn if he is alright. Finn is exhausted and traumatized, however, after having been under the control of the amulet, and does not respond.
- Further reference to the Mushroom War is found in the form of magnetic tourist plates stuck onto Hunson Abadeer's kitchen cabinets. The plates are from Las Vegas, Orlando, and Arizona.
- When Jake is panning over the Nightosphere with his camera phone, he says "This place is bananas," adding to the two-part episode's exhaustive list of banana gags.
- Marceline's demonic head is noticeably greater in this episode as compared to the previous episode, "Return to the Nightosphere."
- The bottle of mustard Hunson gets from the fridge says 'Cut the Mustard' and has a picture of a demon on it.
- When Finn and Jake first meet Marceline (in the previous episode) and think she was her father, some of the features of her head and suit seemed to have different color than the way she appeared in this episode.
- The Nightosphere amulet is seen hanging from a tree branch in the opening theme, though it has a violet chain rather than a gold one.
- Near the end of the episode Finn, wearing the Nightosphere amulet, says the same line Marceline did in the previous episode, both saying "No one leaves the Nightosphere!" This could be a result of the chaotic influence of the Nightosphere amulet.
- In the beginning of the episode, when Jake gets hit by Marceline during the video, he yells, "Ow, my hippocampus!" The hippocampus is the part of the brain that consolidates memories from the short-term and long-term memories and strengthens spatial navigation.
- When Finn is disguised, his mouth seems to be bigger, since it would not be visible at normal size.
- After opening the portal back to the Nightosphere, Jake makes the shaka sign after pointing his finger.
- The sandwich Hunson Abadeer makes is likely a reference to the Dagwood "Midnight Snack" sandwich seen in the comic strip "Blondie."
- During the rap scene, two characters that looks like the spies from the comic strip "Spy vs. Spy" can be seen, just but naked. Even they don´t speak at all, as in the aforementioned strip. They appear into the Half Monster during the previous episode, too.
- This continues the events that had transpired in "Return to the Nightosphere."
- Finn uses the spell he learned in "It Came from the Nightosphere" to open the gate to the Nightosphere.
- The PHIL FACE makes a return from the same episode with Finn drawing it on the wall of the tree house in order to open a portal to the Nightosphere.
- Finn also told Hunson as he was sending him back " I'll see you in the Nightosphere, ya sick freak.", which he does as we see in the phone video telling Marceline "Last time I saw your dad, I sliced open his soul sack."
- In the beginning of the episode, when Marceline came through the portal, her fangs were blunt instead of sharp.
- At the last part of the episode, Marceline's bite mark was mistakenly located at the right of her neck. Also, the bite mark is initially missing, then it appears briefly on the right side, then it disappears again.
- When Hunson makes his sandwich, there is a bite mark in it just before he has a bite. Also, there is already mustard on two layers of the sandwich prior to Hunson even pulling out the mustard bottle from the refrigerator. He may have done the sandwich "build" at the refrigerator.
- Jake's Video Phone switches back and forth from low and high power while they are watching the videos. It is possible that it got damaged in the Nightosphere, however, or maybe it is malfunctioning.
- In "Return to the Nightosphere," Finn and Jake both pop out of the bananas together, but in "Daddy's Little Monster," Finn is tossed into the bananas while Jake is tossed next to them.
- The part of the video that Finn and Jake see in "Return to the Nightosphere" does not actually appear in the video during this episode.
- Near the end Hunson mentions to Marceline how the political rap was "Pretty great", yet he couldn't have heard it since he enters the room after Finn put on the amulet, which was well after the rap song.
This episode was censored in some countries. See Censorship of Adventure Time for more information.