Finn and his friends journey to a lost refuge called Founders Island.
- Bilingual Bonus: Like with Alva and her film reels, the Toy Store Frieda works at has a sign that reads "Leksaker" - Swedish for Toys.
- Clone Army: The Founders Island is patrolled by an army of robot duplicates of Minerva that help anyone in need of assistance.
- The Cobbler's Children Have No Shoes: The ones most hurt when a plague is released on the Founders Island are the Helpers taking care of everyone.Minerva: The fatality rate in the general population grew to 62%. But the fatality rate in Helpers, those who faced the virus daily, was 100%. Or nearly.
- Connected All Along: Susan/Kara was sent from the Island to bring back Finn.
- Continuity Nod: Jake tells a crowd about his time at the flea circus.
- Fantastic Racism: When Jake uses his shapeshifting power, the humans realize he's a mutant and start calling Minerva for help, who imprisons him for disturbing the peace.
- Foil: Minerva is revealed to be one to Princess Bubblegum, being a version of her who never stopped getting more and more dictatorial for the 'good' of her subjects.
- The rat-hybrid Dr. Gross that unleashes the plague by knocking over a beaker is a foil to - of all characters - Science the Rat, who is a rat-hybrid owned by a completely different female mad scientist, and was solely responsible for curing a horrible plague, way back in 'From Bad To Worse'.
- Foreshadowing: Susan knows they're close to the Founders Island because they're "closing in on Minerva's brainwave signature". Turns out that's all there is to find.
- History Repeats: Like when he first met his dad, poor Finn starts out with denial and wants to believe his mom is as great as his brain wants her to be. It turns out better eventually though.
- Instant Sedation: The Minerva robots instantly knock out Finn and Jake using syringes that come out of their fingers.
- Ludicrous Precision:Minerva: You're so big [Finn]! Last time I saw you, you were 6.875 kilograms, and now look at you!
- Not a Mask: Despite sticking out in a city of humans, Jake doesn't initially draw much attention because people assume he's wearing a costume.
- One Dialogue, Two Conversations: Susan speaks to BMO about uncertainty in talking to Frieda, but all BMO does is nod along while playing with some toys.
- Stunned Silence: When a Minerva bot confirms Finn's identity, every single one of them freezes up in silence for a moment.
- Too Much Information: Jake gets a bit too detailed in describing how Finn and his mother act alike.Jake: Minerva's into helping people, just like you. She must have gave you her helper genes as DNA up in her womb with your placenta.
- Unwitting Instigator of Doom: Dr. Gross unleashed a plague that reduced the population of Founders Island by nearly 2/3... when one of her early hybrids knocked over a certain beaker.
- Wham Line: The episode ends on a Cliffhanger while Finn and his mother are mid-conversation.
- Yank the Dog's Chain: Finn seems like he's finally met his mother, who's as great a person as he'd hoped she'd be. Turns out she's moved her body to a computer and become a nigh-dictatorial figure ruling the Islands and won't let him or anyone else leave.